# FIOS Low-pass filter



## ah30k (Jan 9, 2006)

I saw TiVoJerry post this in another thread but the title was unrelated to me so I almost never saw it.

He mentioned FIOS users needing a low-pass filter in addition to attenuation for any TiVos since the TiVo does not play nicely with MoCA.

Anyone have any idea what symptoms would be observable with the 'non playing nicely' comment?

I'm sure many of us FIOS users have little problems here and there and wonder if it could be related.

Anyone have more info???


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## SeanC (Dec 30, 2003)

I saw that post too and it finally tipped me in favor of dumping all the FIOS hardware in my place.

I unplugged the router and cablebox, they'll be going back to verizon.


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## ah30k (Jan 9, 2006)

SeanC said:


> I saw that post too and it finally tipped me in favor of dumping all the FIOS hardware in my place.
> 
> I unplugged the router and cablebox, they'll be going back to verizon.


but I use the MoCA to distribute high speed networking throughout the house using NIMs. If the MoCA causes trouble with TiVo, I'd rather just have the details.


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## SeanC (Dec 30, 2003)

Oh, no doubt. I totally understand that. Since my internet is from a VDSL modem I can choose to dump their MoCA router, which is what I have choosen to do. I agree, most people don't get to make that choice.


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## ilh (Dec 21, 2007)

Since I had already dumped all my Verizon STBs, after seeing Jerry's posting I remembered my ActionTec router was still hooked up to coax. After disconnecting it from the coax, my RS uncorrected/corrected error counts are almost always 0/0, even after 4-10h on channels that used to produce a few hundred uncorrected errors over 1-2h period (e.g., NESN-HD and Discovery-HD).

I think a filter would have to low-pass up to 850MHz with FiOS. I googled around a bit for such a beast, but they seemed a bit pricey. I wonder if Verizon would provide one, perhaps even by mail?

--Lee


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## webin (Feb 13, 2008)

I'm not very technical in the hardware level electronics stuff.... the only reason I know I needed an attenuator was the post that directed me to where to buy them, and I still don't know just how it works.

ilh, could you explain (briefly) what this low-pass filter would be, why one that works "up to 850Mhhz" is expensive, and maybe provide a link to an example?


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## ah30k (Jan 9, 2006)

webin said:


> I'm not very technical in the hardware level electronics stuff.... the only reason I know I needed an attenuator was the post that directed me to where to buy them, and I still don't know just how it works.
> 
> ilh, could you explain (briefly) what this low-pass filter would be, why one that works "up to 850Mhhz" is expensive, and maybe provide a link to an example?


Most receivers expect an input signal within certain limits. Traditional cable plants pump the RF signal throughout a whole neighborhood with many splits & taps so the signal is only moderately strong when it gets to your TiVo. Most tuners operate in this environment so it is natural that they are focused on this level of signal. The RF signal in a Verizon setup is coming just from your ONT on your house and only goes to your house. As a result the signal is usually VERY strong (ie Hot). So strong, in fact, that the receivers in the TiVo clip the input signals. A simple attenuator brings the whole signal down to within limits of the receiver.

The low-pass filter is a different story. The Verizon network utilizes bandwidth above the normal video bandwidth for its whole-home networking using a technology called MoCA. This is the first I heard that the MoCA signals may 'not play nice' with the TiVo (and frankly don't know what that means). A simple fix to this would be to lop-off the MoCA signal above 850MHz using a low-pass filter.

Not sure about pricing.


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## acvthree (Jan 17, 2004)

Ok, I'm outside of my area so this may be pretty stupid...

Splitters usually specify the frequency range, like 5mhz to 1000mhz, doesn't that act like a filter?

Al


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## ah30k (Jan 9, 2006)

acvthree said:


> Ok, I'm outside of my area so this may be pretty stupid...
> 
> Splitters usually specify the frequency range, like 5mhz to 1000mhz, doesn't that act like a filter?
> 
> Al


Saying a splitter is (*good *for 5-1000) is not the same as saying (0-5 and >1000 are zero).

The option of >1000 being crappy could be a result of a 5-1000 splitter.

The filter will make >1000 essentially zero.


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## acvthree (Jan 17, 2004)

Ah, I see. Like I said, out of my area. Thanks.

al


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## ilh (Dec 21, 2007)

I might not have looked hard enough, or they are just not that common enough to drive prices down.

If someone finds a good filter for FiOS MoCA, I'd love to hear about it. If someone has one installed by Verizon, please let us know what exactly it is, brand and part number if possible.


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## aaronwt (Jan 31, 2002)

I've had no problems with my four TiVo boxes on FiOS. I have one FIOS STB connected to the actiontec router and this hasn't caused any problems with my TiVo boxes. I do have the cable going through an 8 way splitter first since the signal is so hot.


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## acvthree (Jan 17, 2004)

Interesting. My installer also used an 8-way splitter to cool the hot signal and I've had no problems with the signal.

We had people who have had success using attenuators, but we've also had a few with on going problem that seemed never to completely clear up. The low-pass filter to cover MoCA problems seems like a good hypothesis.

Al


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## lrhorer (Aug 31, 2003)

ah30k said:


> Most receivers expect an input signal within certain limits.


Not most, all. Every receiver has a limit to its sensitivity and at some point will overload.



ah30k said:


> Traditional cable plants pump the RF signal throughout a whole neighborhood with many splits & taps


'Not relevant. The CATV system is engineered to have a level within a specific range for each and every tap. Of course the ideal goal is to have the signal just barely reach the last tap in the line, but even in those cases where the feeder line is very short (meaning very few splits and taps), the signal parameters are the same as a much longer or more branched feeder leg. For example, before I left my post as an engineer at the local CATV system quite some years ago, the spec for every tap was no less than +7 dBmV on channel 2 and no less than +9 dB on channel 50, which was the highest channel in the lineup at the time. Since tap values are staged in 3dB increments, this meant in practice the signal level close to the amplifier would vary between +7 and +10 dBmV on channel 2, with channel 50 being as high as +19 dBmV, and towards the end of the plant the signal on channel 50 wouuld be between +9 and +12 dBmV, with channel 2 being possibly as high as +21 dBmV measured right at the tap. Shortly before I left they began to design for a minimum of +10 / +12 dBmV at the tap.



ah30k said:


> The RF signal in a Verizon setup is coming just from your ONT on your house and only goes to your house. As a result the signal is usually VERY strong (ie Hot).


Again, this isn't really relevant. Levels on the output of a bridger or line extender may exceed +50 dBmV on the highest analog channels. The Verizon modulator doesn't produce levels that high. By design, the output levels are attenuated by as much as 32dB to bring them in line with the system specs.



ah30k said:


> So strong, in fact, that the receivers in the TiVo clip the input signals.


Not. Signal clipping on a 750 MHz broadband signal isn't going to happen until the signal is so hot it is practically melting the unit. What happens is second and especially third order distortions begin to be significantly high in the receiver's superhet mixer. Beyond a certain limit, these will cause the signal to be unrecoverable. A little below that level, the receiver will still produce significant amounts of errors. High levels can also cause problems with adjacent signal rejection, but most receivers have an AGC which calms this effect fairly well.



ah30k said:


> A simple attenuator brings the whole signal down to within limits of the receiver.


'Correct.



ah30k said:


> The Verizon network utilizes bandwidth above the normal video bandwidth for its whole-home networking using a technology called MoCA. This is the first I heard that the MoCA signals may 'not play nice' with the TiVo (and frankly don't know what that means).


It's the first I have heard of it, as well, but it's certainly not impossible. Depending on what LO frequency the TiVo is using for its tuners, exceeding the LO by a significant amount can definitely cause grief. One can get mirrored beats in the mixer, basically putting two channels into the final gain stage where there should only be one. Not only that, but the amount of distortion in the receiver goes up with the number of channels in the spectrum, so any information outside the normal tuning range is an extra and unnecessary burden on the receiver.


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## aaronwt (Jan 31, 2002)

According to my FIOS router, the MoCA frequency used is 1150Mhz.
The FIOS STB box specs show that it's designed to work between 1125Mhz and 1425 MHz for MoCA.
And it's designed to work between 54 to 860 MHz for QAM video.


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## dslunceford (Oct 19, 2000)

Can someone post a link to TiVoJerry's orig post on this? I have one box that gives me problems. TiVo sent a replacement and it still exhibited the issue (so the replacement went back), so it's a signal issue somehow. VZ has been out to look at it, but still couldn't fix; attenuators don't fix either, and getting rid of MOCA doesn't seem to be an option.

We are in process of dropping analog and adding new HDs, so I don't want to mess with this until then, as that switch may bring more changes, but want to be ready to call VZ up and see if they can try this option. Getting rid of MOCA isn't an option as I use the Actiontec for Internet, plus have NIMs feeding the TiVos for networking.

It would be nice if TiVo believes this is isolated/"the" issue, that they could work on a fix with VZ in terms of ensuring what needs to be done.


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## moyekj (Jan 24, 2006)

dslunceford said:


> Can someone post a link to TiVoJerry's orig post on this?


http://www.tivocommunity.com/tivo-vb/showthread.php?p=6373210#post6373210
As I've stated in another thread I use MOCA with Motorola NIM100s to network my S3s and do not have any issues (and I have no filter installed).


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## ah30k (Jan 9, 2006)

I wish the symptom were more accurately described so we would know if that fix will have any impact on our situation. I'd hate to go buy a filter if it won't help.


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## hmm52 (Feb 25, 2008)

I'm reconnecting coax to router and removing the filter tonight.

Any suggestions for loading the test to make it worthwhile?

Currently CAT-5 connects all computers & TiVo to Actiontec, which is CAT-5ed to ONT. One VZ STB connected & powered. Connect, disconnect, or introduce anything else? 

Today's FiOS feed is offering medium to heavy tiling on the local HDs; moderate tiling on a few others checked. (without attenuation) I assume the menu will be more or less the same this evening. I'll note RS Uncorrected over time both ways on the offenders and quick scan for pixelation elsewhere. More?

My money is on no difference.


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## Phantom Gremlin (Jun 20, 2002)

There may be a cheap and simple way to buy a low-pass filter. The frequencies in question are very similar to what is needed in sharing a single coax between cable and DirecTV.

For details of how it's done in the DirecTV world, see this post.

Here's a typical product. Dirt cheap. Notice the markings, an input is split into a 5-860 MHz output and a 950-2300 MHz output.

I don't have FiOS, so I don't have any reason to investigate this further (the devil is in the details). Consider this as a starting point for someone with problems.


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## bhaas (Aug 5, 2003)

the diplexer might work- it is a type of filter, and should have very good isolation between the bands (>25dB). Probably any DBS/Dish/DirecTV diplexer will work. However it is IMPERATIVE that the "sat" output be capped with a 75-ohm terminator to prevent reflections back into the house cabling- you can buy them cheaply at radioshack.

A regular 'lowpass filter' at these frequencies is expensive because this range is in the cellphone and L-band microwave transmission realm, and 75 Ohm impedances with F-connectors are not used, so what you do find will be rare, which means expensive. A 1GHz lowpass with 50 Ohm SMA connectors is about $20, but is not a good solution for home cabling.

btw- I agree with lrhorer. Assuming the MoCA signal is a real issue, chances are good that an imaged beat or IMD is being presented to the last stage, effectively jamming the intended signal. I just beat some of those same gremlins out of a link I'm working on.


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## ira_l (Sep 23, 2002)

I had a Verizon repairperson come by last week and showed him the posting from TiVoJerry. He installed a low pass filter inside my ONT and we removed ALL attenuators from my two Series3 TiVos.

Now, I have no pixellation problems on ANY channel and my signal strength is 95-100 on all channels. SNR is 35-37.

YMMV and this may not work for you, but based upon what I've seen, I HIGHLY recommend any FiOS customers who are experiencing pixellation problems go this route. The nice guy from Verizon did not charge for the visit. He was unaware of this issue and thanked me for working on it with him. He learned something which could benefit his customers.

THANK YOU TivoJerry!!!!!


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## DCIFRTHS (Jan 6, 2000)

ira_l said:


> I had a Verizon repairperson come by last week and showed him the posting from TiVoJerry. He installed a low pass filter inside my ONT and we removed ALL attenuators from my two Series3 TiVos.
> 
> Now, I have no pixellation problems on ANY channel and my signal strength is 95-100 on all channels. SNR is 35-37.
> 
> ...


Glad your problem is solved, and kudos to the tech for having an open mind 

EDIT: Would you mind listing your setup? Is the internet portion using coax ro ethernet from the ONT? Do you have any of the FiOS cable boxes hooked up?

Is there any way you can post a pic of the device installed? You mentioned that it was installed *inside* the ONT. Is that accurate? Thanks!


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## ira_l (Sep 23, 2002)

DCIFRTHS said:


> Glad your problem is solved, and kudos to the tech for having an open mind
> 
> EDIT: Would you mind listing your setup? Is the internet portion using coax ro ethernet from the ONT? Do you have any of the FiOS cable boxes hooked up?
> 
> Is there any way you can post a pic of the device installed? You mentioned that it was installed *inside* the ONT. Is that accurate? Thanks!


Sure, no problem. I have two Series3s, one Motorola SD set-top box and one digital adapter. I have the Actiontec router which was installed in January when I got FiOS TV installed. I had been a FiOS Internet customer for two years - the Actiontec router replaced the D-Link that Verizon gave me previously.

The ONT is on the wall right outside the Actiontec so both CAT5 and RG-6 come through the wall and into the Actiontec. Elsewhere in the house is a 4 way splitter which provides FiOS TV to the other TVs in the house. My house-wide Ethernet cabling had been set up by me years ago. The Verizon tech didn't disturb it. I do have a second router, a Linksys WRT54G which provides more wireless capabilities in a different part of the house.

The LowPass filter IS mounted INSIDE THE ONT. It is silver and looks like a fat Male to Female F connector adapter with no markings. It's about 1 1/2 inches long.

Hope that helps!


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## thegeek (Dec 16, 2002)

I'm curious how dropping a low pass in the ONT helps. Sounds like your data is provisioned to go over the ethernet. This means that there's shouldn't be any MoCA riding over that part of the RG6 network other than what's being generated from inside the house by the STB and the Actiontec. No MoCA signals should be coming out of the ONT.

I suspect if you look at the LEDs on the customer access side of the ONT, the MoCA light is not illuminated. That's even assuming your ONT is even MoCA-capable, which given that they tossed you a D-Link to start off with, it probably isn't.


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## ira_l (Sep 23, 2002)

thegeek said:


> I'm curious how dropping a low pass in the ONT helps. Sounds like your data is provisioned to go over the ethernet. This means that there's shouldn't be any MoCA riding over that part of the RG6 network other than what's being generated from inside the house by the STB and the Actiontec. No MoCA signals should be coming out of the ONT.
> 
> I suspect if you look at the LEDs on the customer access side of the ONT, the MoCA light is not illuminated. That's even assuming your ONT is even MoCA-capable, which given that they tossed you a D-Link to start off with, it probably isn't.


My Motorola SD Set-Top Box is receiving PPV and VOD so I suspect you're wrong.


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## ira_l (Sep 23, 2002)

DCIFRTHS said:


> Is there any way you can post a pic of the device installed? You mentioned that it was installed *inside* the ONT. Is that accurate? Thanks!


Here's a picture. I was inaccurate in my previous post. The Low Pass Filter *is* actually *labeled* "5-860MHz Low Pass Filter." See it on the right side connected to the white coax? The peach colored CAT-5 cable can be seen on the left side.

Picture can be seen at http://www.mediafire.com/imageview.php?quickkey=yyrm1jpjbnm&thumb=4










Illuminated lights are Power, Battery, Network, OMI, Link and 100MBPS. This is a Model ONT611 ONT.


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## litkaj (Jun 5, 2007)

ira_l said:


> Here's a picture. I was inaccurate in my previous post. The Low Pass Filter *is* actually *labeled* "5-860MHz Low Pass Filter." See it on the right side connected to the white coax? The peach colored CAT-5 cable can be seen on the left side.
> 
> Picture can be seen at http://www.mediafire.com/imageview.php?quickkey=yyrm1jpjbnm&thumb=4
> 
> ...


Is there a part number or manufacturer on that? I've been trying to find one of those for quite a while and am striking out...


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## ira_l (Sep 23, 2002)

litkaj said:


> Is there a part number or manufacturer on that? I've been trying to find one of those for quite a while and am striking out...


No, there isn't. Verizon gave me one for free. Why would you want to buy one?


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## litkaj (Jun 5, 2007)

ira_l said:


> No, there isn't. Verizon gave me one for free. Why would you want to buy one?


Because in order to get them to come out I've got to take a day off work (and I make a hell of a lot more per day than the $10 this filter will cost).

Anyway, I've found tons of places selling 5-750MHz filters but none selling these 5-860 models. I found a manufacturer overseas but that's not going to help...


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## ira_l (Sep 23, 2002)

litkaj said:


> Because in order to get them to come out I've got to take a day off work (and I make a hell of a lot more per day than the $10 this filter will cost).
> 
> Anyway, I've found tons of places selling 5-750MHz filters but none selling these 5-860 models. I found a manufacturer overseas but that's not going to help...


Of course! Sorry, I should have thought of that!  I'll see if I can find one online and post here if I do. Otherwise, you could try calling Verizon and asking if they would send you one, citing others who have gotten this simple device installed. It might be worth a shot; the worst they could say is no.


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## DCIFRTHS (Jan 6, 2000)

ira_l said:


> Here's a picture. I was inaccurate in my previous post. The Low Pass Filter *is* actually *labeled* "5-860MHz Low Pass Filter." See it on the right side connected to the white coax? The peach colored CAT-5 cable can be seen on the left side.
> 
> Picture can be seen at http://www.mediafire.com/imageview.php?quickkey=yyrm1jpjbnm&thumb=4
> 
> ...


 .


Thanks for the pics 

I did some research after reading your post, and I found the post below on DSL Reports, posted by "originalvztech", and seems to answer the questions I had regarding what this filter does (kind of obvious), and why it corrects the problem. The post is quoted in its entirety, but here is the link. According to the post below, this problem does not affect all ONTs, but yours is one of the affected models.



> If you have problems with FiOS TV....
> 
> If you are having problems with FiOS TV either pixelating/tiling/artifacting and have a 611i ONT (White ONT with 4 POTS ports, NO MOCA) or a Motorola 1000V and no one has been able to resolve the issue, check to make sure a low pass filter, MoCA Diplexer, or MOCA NID has been installed on the coax feed immediately after the ONT. There is a known issue that affects only these two types of ONTs. Basically, the video signal when tested appears to be normal and within specifications and so the tech doesn't seem to find anything wrong with the video signal out of the ONT. The actual cause however is isolated to a defect in the ONT Triplexer. What happens is that the MOCA from the Actiontec router or the motorola nim backfeeds into the ONT. The ONT is supposed to have a triplexer that keeps those signals from interefering with each other. To fix the problem, the Moca Lan signal (1125mhz-1175mhz) needs to be filtered out of the coaxial network prior to reaching the ONT 611i or ONT 1000V. The best way is to place a low pass filter immediately after the ONT which will pass through 5-860MHz video signal, but not allow the 1125-1175Mhz moca signal from the router to reach the ONT. This signal only needs to travel between router and set-top boxes. If a low pass filter is unavailable, then a diplexer or moca nid may be used. Please note this does not affect the MOCA cable ONT's such as the Tellabs 612, or the Motorola 1000M. If you are having problems with your TV service and everything else has been tried and you have this particular model ONT, make sure the technician tries this. If he has any questions tell him to refer to Doc. No. 2007-00021-MDP Issue C for methods and procedures.
> Thought I would post this for those who may have this issue since unfortunately not every tech reads the methods and procedures or knows about this issue.


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## DCIFRTHS (Jan 6, 2000)

litkaj said:


> Because in order to get them to come out I've got to take a day off work (and I make a hell of a lot more per day than the $10 this filter will cost).


Check to see if Verizon will schedule a weekend appointment. I know they do it where I am located. Give it a shot.



litkaj said:


> Anyway, I've found tons of places selling 5-750MHz filters but none selling these 5-860 models. I found a manufacturer overseas but that's not going to help...


If you find any sources, please post back, as I am interested in locating them too.


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## ira_l (Sep 23, 2002)

DCIFRTHS said:


> .
> 
> 
> Thanks for the pics
> ...


You're welcome and thanks for that info! I'm sorta glad I have one of the "affected models," since the fix was instantaneous - like flipping a switch. The six months of pixellation was annoying, but now everything looks amazing!


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## litkaj (Jun 5, 2007)

DCIFRTHS said:


> Check to see if Verizon will schedule a weekend appointment. I know they do it where I am located. Give it a shot.


Yeah, they do those here as well. The problem is that they give a window of 8:00 AM until 6:00 PM.


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## urkel-Os (Oct 23, 2005)

I have a 611 ONT and a THD with the same pixellation problems described many times on this forum. I cannot get acceptable results with attenuators. There is no sweet spot that gets rid of the macroblocking but leaves a strong enough signal so that all channels can be tuned, and the signal strength at the THD seems to be all over the place. I tried to locate an appropriate filter or MOCA diplexer on the Internet so that I could just take care of this myself, but no luck.

So, last week I called Verizon and requested they send someone to my house to install a low-pass filter, and the rep said he'd never heard about this fix, and neither did the tech guy that he consulted while I was on hold. The rep said they'd send someone anyhow, and when he read back the ticket notes to me at the end of the call, he seemed to have got the gist of the request. When the tech got here, all he did was check the signal on the line going into the THD. I explained to him the situation and even showed him parts of this thread. After that, he got a bit more interested, but he said he didn't know anything about low-pass filters, etc. He even called a couple of other guys on his crew, and they didn't know anything about it either. 

The tech also mentioned that the hardware at my CO is not compatible with the newer ONTs that do not have this issue, so that's not even an option. When he left, he said he'd check back at the garage (or whatever he called it) to see if they had any filters or MOCA diplexers and get back to me this week. At least he didn't try to close the ticket, but I am not confident he's going to find the right hardware at the garage. So I'm starting to wonder if there's a magic word that I need to use with these folks in order to get them to try what is probably the correct solution to the problem. Or maybe it is a catch-as-catch-can situation where techs in different regions have access to different hardware supplies -- which means maybe I can get a VZ office in another region to send me a filter. The reason I wonder is that ira_l, who posted the photo showing the filter in the ONT is in NY State, while I am in Howard County, MD. 

Does anyone know where I can find the appropriate hardware myself for a reasonable price? Thanks for any input...


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## ira_l (Sep 23, 2002)

urkel-Os said:


> The reason I wonder is that ira_l, who posted the photo showing the filter in the ONT is in NY State, while I am in Howard County, MD.
> 
> Does anyone know where I can find the appropriate hardware myself for a reasonable price? Thanks for any input...


The Verizon tech here in upstate NY who installed the Low Pass Filter in my ONT was using a colleague's truck the day that he was here, but he DID know what a Low Pass Filter was and quickly located one in the truck. He was a former TiVo customer, dating back to before FiOS was available around here, and was very interested in the situation and its resolution.

I think that word just has to get out. The Verizon techs that I have had over here do get training and keep up with what's new since the technology is constantly changing.

I can't guarantee results, of course, but perhaps you could just call again and explain the situation, point them at the photo that I posted and ask them to get you the same solution that works so well elsewhere in their system.

Good luck!!!


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## acvthree (Jan 17, 2004)

I thought I remembered someone her having published the verizon tech note with the tech note number. I did a search and couldn't find it. Maybe someone with better search skills could help out.

Al


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## ira_l (Sep 23, 2002)

acvthree said:


> I thought I remembered someone her having published the verizon tech note with the tech note number. I did a search and couldn't find it. Maybe someone with better search skills could help out.
> 
> Al


Doc. No. 2007-00021-MDP Issue C for methods and procedures.

Here's the discussion of it on dslreports.com.


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## DCIFRTHS (Jan 6, 2000)

acvthree said:


> I thought I remembered someone her having published the verizon tech note with the tech note number. I did a search and couldn't find it. Maybe someone with better search skills could help out.
> 
> Al


That was me . Here's my post on this forum, but the post above gives the same information.


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## acvthree (Jan 17, 2004)

Yep, that was it! Thanks. My search skill failed me. 

Al


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## urkel-Os (Oct 23, 2005)

Thanks for the support! Yeah, I should have mentioned that document, but I was trying to convey as much information as possible without causing the tech's eyes to glaze over with boredom. I don't necessarily blame these guys for getting a little irritated when they think a customer is trying to tell them how to do their job. Which I was. If he gets back to me (which I'm really not expecting), I'll mention that document, although I have a feeling it will be more helpful to bring that up with phone support or similar. I'll give VZ another couple of days, and then if they can't help, I'm going to order the satellite diplexer that Phantom Gremlin linked to in post #20 of this thread. Never bought anything from that company before, but they appear reputable.

Ok, here comes a conspicuous display of ignorance -- if I hook up the diplexer in the ONT housing, does orientation matter? I know the SAT port just gets a 75-ohm terminator, but does it make a difference whether I connect the IN port to the RF OUT port on the ONT or to the coax leaving the ONT? Is there any directionality? My guess is that it makes no difference, but I can't quite sort it out. Thanks...


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## Ziggy86 (Jun 23, 2004)

ira_l said:


> Here's a picture. I was inaccurate in my previous post. The Low Pass Filter *is* actually *labeled* "5-860MHz Low Pass Filter." See it on the right side connected to the white coax? The peach colored CAT-5 cable can be seen on the left side.
> 
> Picture can be seen at http://www.mediafire.com/imageview.php?quickkey=yyrm1jpjbnm&thumb=4
> 
> ...


Is this considered an old or new model ONT611?


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## aaronwt (Jan 31, 2002)

That looks like the one I have that was installed Summer 2007.
Althouh I don't know if it's the same model.


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## ira_l (Sep 23, 2002)

Ziggy86 said:


> Is this considered an old or new model ONT611?


Old. Mine was installed in January 2006.


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## urkel-Os (Oct 23, 2005)

Ok, here's an update on my quest for VZ to put a low-pass filter on my 611 ONT. Never heard anything back from the tech who initially visited my house (the one who just checked the signal in the cable that connects to the THD), so I called VZ back and asked about the status of that ticket. I was told it had been closed! This got me going, and the phone rep was very apologetic. He took down the info from me about the problem I was having with pixellation and how I needed a low-pass filter on the ONT, etc. Then, I referenced the document mentioned in this thread. He appeared to be taking everything down and was very polite. He gave me a confirmation number and told me that I would receive a phone call from a real (i.e., escalated level) tech support person within the next 23(?) hours. I then left for work.

When I returned home around 7:30, there was a VZ service report pamphlet on my door, but none of the information was filled out. I checked my phone mail, and VZ dispatch had left a message around 4:00 saying that a tech was at my house and needed to gain access to the premises. Well that's just super! Remember, the phone rep told me to expect a call from tech support. I was never told that someone would be visiting my house that day, and was never asked if I would be available then either. I was so annoyed that I decided to wait until the following day (today) before putting in another call to VZ.

So I called VZ this morning, and had to repeat the same song and dance number as the previous day because -- wait for it -- yesterday's ticket had been closed. Now, more apologies from the phone rep. I ask if he can access the notes from yesterday's ticket, but apparently that was not possible. WTF?!? After giving him the same _very_ detailed info as the previous phone drone, I get another confirmation number, and he says that I will be hearing from a VZ network tech within a couple of days. As a backup plan, I have gone ahead and ordered an Eagle Aspen diplexer on the assumption that VZ will never get this right. By "right" I mean that someone from VZ will come out at an agreed-upon time and try something that has a chance of solving the pixellation issue. I am tired of spending time on this and really wish I'd been able to locate an LPF with the same specs as the one in ira_l's photo so that I could have just done it myself in the first place.


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## Ziggy86 (Jun 23, 2004)

Urkel,

Keep us posted. Verizon was in my neighborhood last week trying to sell us on the Fios TV that just became available in our area. I am holding off hoping they fix these type of issues before I go ahead and make the change from Time Warner.

The sales person told us that Fios TV is NOT compatible with Tivo, can you believe that, I guess they want to sell their own DVR's and hope by saying that people will switch, what a lie!!!!!!

Steven


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## RPeppe (Feb 17, 2002)

Same problems with picture breaking up, freezing, audio dropping out. Called, explained the problem. Had printouts of this and related threads when tech arrived, but he insisted this was nonsense, said my signal was fine, and said Verizon policy is to not support any Tivo problems. I showed him the document number and he said it was made up and does not exist. Verizon refused to do anything else. We actually tried the Verizon DVR before springing for the Tivo HR, but it had its own problems with the picture breaking up, even after a replacement, aside from the interface that did not compare to the Tivo. Grrrrr.


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## bhaas (Aug 5, 2003)

Tivo support article 05-12-01:

" 'Macroblocking' refers to areas of your television screen that do not display the correct image, but instead contain blocks of a single color. Most cable customers notice occasional instances of transient macroblocking.

If you are using Verizon FIOS service with a TiVo HD DVR or TiVo Series 3 HD DVR, however, you may see frequent macroblocking and widely fluctuating signal levels. This issue can be resolved easily by installing a low-pass filter or diplexer in the cable line.

Verizon technical support is aware of this issue and the necessary steps to resolve it. Please contact them at http://www22.verizon.com/Residential/Support/ContactUs to request the installation of a low-pass filter or diplexer."


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## jhimmel (Dec 27, 2002)

It would be so much easier if we could just locate a source so that we could purchase and install this low-cost item ourselves.

I never suffered too much from these symptoms, -UNTIL- the re-alignment. Now I have a number of channels that suffer pretty badly from these symptoms. Would love to try the low-pass filter.

Jim H.


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## JacksTiVo (Jan 7, 2006)

I did not search the entire thread to see if anyone else has tried this scheme to correct pixelation. For what it is worth, I put a standard two port coax cable splitter just before my S3. This attenuates the signal by about 2.5db. Don't forget to attach a 75 ohm dead-end cap onto the unused port on the splitter. My FiOS ONT coaxial output also splits to the Internet modem and two other TV's so by the time the signal arrives to the S3 it is attenuated by 7.5 - 10db.

Has anyone else tried this?


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## urkel-Os (Oct 23, 2005)

RPeppe said:


> Same problems with picture breaking up, freezing, audio dropping out. Called, explained the problem. Had printouts of this and related threads when tech arrived, but he insisted this was nonsense, said my signal was fine, and said Verizon policy is to not support any Tivo problems. I showed him the document number and he said it was made up and does not exist. Verizon refused to do anything else.


Well, fellow Marylander, looks like we've both led the VZ horse to water, but are having trouble getting it to drink. This morning, a VZ network tech called to make an appointment to send a field tech to (hopefully) fix the problem. At least he was familiar with the concept of a low-pass filter and seemed to have some grasp of the situation. Will post an update after the field tech visit.


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## urkel-Os (Oct 23, 2005)

JacksTiVo said:


> I did not search the entire thread to see if anyone else has tried this scheme to correct pixelation. For what it is worth, I put a standard two port coax cable splitter just before my S3. This attenuates the signal by about 2.5db. Don't forget to attach a 75 ohm dead-end cap onto the unused port on the splitter. My FiOS ONT coaxial output also splits to the Internet modem and two other TV's so by the time the signal arrives to the S3 it is attenuated by 7.5 - 10db.
> 
> Has anyone else tried this?


I think there's a lot of variability in how much attenuation folks use to tone down the pixellation. I have a 4-way splitter in front of the ONT, plus 13db of inline attenuation on the THD line, and it's still not enough to prevent pixellation on some channels. At the same time, the signal is too weak on certain other channels to receive a picture at all on the very same TV. This is why I'm going through hoops trying to get VZ to install a low-pass filter on my model 611 ONT, which is one of the models that has a known issue with pixellation.


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## JacksTiVo (Jan 7, 2006)

urkel-Os said:


> I think there's a lot of variability in how much attenuation folks use to tone down the pixellation. I have a 4-way splitter in front of the ONT, plus 13db of inline attenuation on the THD line, and it's still not enough to prevent pixellation on some channels. At the same time, the signal is too weak on certain other channels to receive a picture at all on the very same TV. This is why I'm going through hoops trying to get VZ to install a low-pass filter on my model 611 ONT, which is one of the models that has a known issue with pixellation.


I just checked and my model ONT is 612, perhaps that is why I am not experiencing the problems.


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## lrhorer (Aug 31, 2003)

Ziggy86 said:


> The sales person told us that Fios TV is NOT compatible with Tivo, can you believe that, I guess they want to sell their own DVR's and hope by saying that people will switch, what a lie!!!!!!


The next time someone tries that on you, ask them for their full name and employee number, and then explain to them you will be sending out a letter to the FCC with a copy going to Ivan Seidenberg, CEO of Verizon Inc., informing them <insert sales rep's name> explicitly stated in a conversation with you on <insert date> that Verizon is knowingly and willfully in violation of the FCC regulations pursuant to the Federal Telecommunications act of 1996 concerning the required compatibility with third party separable security devices after July 1, 2007, preventing their system from working with a certified CablkeCard 1.0 device. You might just happen to mention failing to comply with federal regulations can elicit fines in excess of $100,000 a day until the situation is resolved.

It's a bluff, of course, but there's no way the sales rep can know that, and it will scare the bejeezus out of the odious toad, which is no less than he deserves.


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## lrhorer (Aug 31, 2003)

urkel-Os said:


> I think there's a lot of variability in how much attenuation folks use to tone down the pixellation. I have a 4-way splitter in front of the ONT, plus 13db of inline attenuation on the THD line, and it's still not enough to prevent pixellation on some channels. At the same time, the signal is too weak on certain other channels to receive a picture at all on the very same TV. This is why I'm going through hoops trying to get VZ to install a low-pass filter on my model 611 ONT, which is one of the models that has a known issue with pixellation.


It sounds like an equalizer might also be in order. With the signal source only being a few meters away, an equalizer should not be required, but I suppose one never knows. You might have Verizon check the signal flatness from end-to end in the spectrum. The highest signal should be no more than 9 dB above the lowest, after adjusting for analog vs. digital signal levels. (Digital signals may be run as much as 20dB below analog signal levels.) The thing is, equalizers designed for the subscriber drop are much harder by which to come than attenuators.

I did find at least one equalizer (also called a "tilt compensator"), the TSEQ-2150-12 for $6.59, but it would only be useful if it is your lower frequencies which are high in signal level compared the higher frequencies. Blonder Tongue also makes the LE-860 series of equalizers in values of 3, 6, 9, 12, 15, and 18dB, but I don't know of a source or pricing for these. Once again, however, these will only correct the situation where the low frequency carriers have higher signal levels than the high frequency carriers. Your situation might be the opposite, with the high frequency carriers being too high compared to the lower frequencies. You also might be experiencing a flatness problem not uniform throughout the spectrum, wherein the low and high frequencies are roughly the same, but carriers in the middle of the spectrum are either much lower or higher than they should be.

The bottom line, however, is that unless the flatness issue is due to the RF equipment (splitters, amplifiers, etc) and cabling inside your house, then it's Verizon's problem, not yours. Get them to bring out an RF spectrum analyzer (it's likely not every technician carries one of these, although they have become much cheaper in the last 20 years) and have him show you the spectrum at the input to your house wiring. The peaks of the carriers should form a nice, fairly flat line from end to end. The line may be slightly tilted (take note of the screen resolution: if the SA is set for 20 dB per division, the spectrum is going to look quite flat, no matter what. Make sure the screen is set for no more than 10dB per division), but not grandiosely so, and there shouldn't be any huge peaks or valleys. Below is an image of a nice, fairly flat CATV RF spectrum at 10dB / division. Note the pictured analyzer costs $15,600, which is why not every tech carries one.


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## lrhorer (Aug 31, 2003)

JacksTiVo said:


> For what it is worth, I put a standard two port coax cable splitter just before my S3. This attenuates the signal by about 2.5db.


Uh-uh, not quite. A hypothetically perfect symmetrical, lossless split of any signal will result in two signals 3.0103 dB lower than the original signal. In practice, a high quality CATV RF splitter will produce two signals roughly 3.5 dB lower than the original signal at 50 MHz. Typically the attenuation at 1000 MHz of a quality CATV RF splitter specified for 1000MHz use is about 4 - 4.5 dB. Poor quality splitters may have either or both a somewhat higher flat loss and tilt loss. At a minimum, the splitter you used represents at least a 3.5 dB attenuation, not 2.5 dB. Oh, and it is dB, not db. The lower case letter "d" is the internationally recognized standard abbreviation prefix meaning "deci-" or a factor of 1/10. The upper case "B" is the standard abbreviation for "Bel", named in honor of Alexander Graham Bell, and represents the base ten logarithm of the ratio of two power measurements. One dB is one decibel, one tenth of a bel, or a factor of 1.26. A factor of two is 3.0103 dB. A factor of 10 is 10 dB, or 1 bel.



JacksTiVo said:


> My FiOS ONT coaxial output also splits to the Internet modem and two other TV's so by the time the signal arrives to the S3 it is attenuated by 7.5 - 10db.


They may be using a directional coupler to feed the modem, rather than a symmetrical splitter. A DC 12 will have about a 0.4dB through loss and a 12dB tap loss. The actual loss from the ONT to your TiVo depends on how the split is done and how long your subscriber drops are. At 50 MHz, the attenuation in RG-6 cable is about 0.049 dB/meter, while at 850 MHz, the attenuation is about 0.230 dB/meter. As you can see, that is quite a difference. A 100 meter subscriber drop will attenuate the lowset downstream carriers by less than 5 dB, while the highest carriers (on a FIOS system) are attenuated by a whopping 23dB! While 100 meter subscriber drops are not the norm, there are many houses in which one or more drops exceed 100 meters, so the equalizers mentioned in the previous message may be appropriate for some houses. In your case, if they used a DC-12 and a 4-way splitter to deliver the service to your three TVs, then after your splitter there is a minimum of 11 dB of flat loss, plus whatever cable loss is incurred in your drop. If they simply used a 4-way splitter to deliver the service to all four devices, and it's a very short distance to your TiVo, then maybe we're talking about 10.5 dB at 50 MHz. Twelve dB is probably more like it, and 15 dB or more at the high end.


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## DCIFRTHS (Jan 6, 2000)

jhimmel said:


> It would be so much easier if we could just locate a source so that we could purchase and install this low-cost item ourselves.
> ...


I also wish this filter could be easily purchased by hte end user...


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## Phantom Gremlin (Jun 20, 2002)

lrhorer said:


> You might have Verizon check the signal flatness from end-to end in the spectrum. The highest signal should be no more than 9 dB above the lowest, after adjusting for analog vs. digital signal levels. (Digital signals may be run as much as 20dB below analog signal levels.)


That's an interesting tidbit of information.

I haven't tried FiOS yet, for a variety of reasons. But I know that in my area FiOS is all digital, no analog. So does that mean I'm less likely to have a problem with varying signal levels than in other parts of the country? I.e. it should be much easier for the ONT to supply "flat" signals if all it needs to output is just QAM and not some (digital) QAM plus some (analog) NTSC. Does that make sense?


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## lrhorer (Aug 31, 2003)

Phantom Gremlin said:


> But I know that in my area FiOS is all digital, no analog. So does that mean I'm less likely to have a problem with varying signal levels than in other parts of the country?


No. Spectrum flatness is an artifact of the physical configuration of the plant. It has nothing to do with the type of carriers in the spectrum. If something - anything - is causing one part of the spectrum to be attenuated more than another, or if the levels of the carriers are improperly set in the first place, then you may experience problems. This whether the carriers are analog, digital, or a mixture of both. Analog and digital signals suffer differently and to different extents if signal levels are not nominal - either too high or too low, but the mixture of analog and digital signals will not impact the spectrum flatness.



Phantom Gremlin said:


> I.e. it should be much easier for the ONT to supply "flat" signals if all it needs to output is just QAM and not some (digital) QAM plus some (analog) NTSC. Does that make sense?


It makes sense in that I know what you are asking, but no, it's not really any more difficult to balance signal levels whether the carriers are all one type or not, and cables, amplifiers, and passive devices all have the same effect on signals regardless of the type of carriers. If the output of the ONT is perfectly flat and the signal goes through 100 meters of RG-6 cable, then at the end of the cable the channel sitting right at 860 MHz will be 18 dB lower than the one at 55.35 MHz. This could present a problem, although the output of the ONT is probably (deliberately) tilted in the other direction, so that the level at the TiVo may only be tilted by 8 or 9 dB. It's also likely your house drops are less than 100 meters in length. Most are less than 30 meters.

I don't know for certain, as I am not intimately familiar with FIOS ONTs, but I would expect the ONT to have controls for slope and gain so that proper levels can be obtained. I also don't know for certain what FIOS' engineering specifications are, but I would think they would set up their signals with about a 7 to 10 dB slope, the highest frequency carriers being 7 - 10 dB higher in level than the lowest carrier, if the carriers are all of one type. If the lineup is mixed, then I would expect the same tilt across the spectrum, but I would expect the digital carriers to be perhaps 10, 15, or even possibly 20 dB lower than an analog carrier ould be if it were at the same frequency.


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## urkel-Os (Oct 23, 2005)

The good news is that VZ finally sent someone to my house with a low-pass filter, and he installed it in the ONT as I requested. Only took four field tech visits!

The bad news is that I'm still seeing bad pixellation on some national HD channels. The symptoms are identical to what jmr50 posted here. As I'm watching right now, it's only bad on ESPN2HD and HDNETMV, which are both at 735 MHz. There are no inline attenuators connected anymore, so it's possible that there would be some improvement if I messed with those, but I'm pretty disappointed that the LPF did not clear up the problem on its own as others have noted. Fyi, according to the tech's meter, I should apply approximately 21 dB of attenuation. We tried that, and it didn't eliminate the pixellation. At least he left me with a big handful of attenuators in case I decide to tinker with that again.

So it looks like the best chance of solving the problem at this point would be for VZ to upgrade the CO so that I can get a better ONT, or if the upcoming channel realignment resulted in channels I don't watch being located at 717/723/735 MHz -- like WEALTHHD. Anyone know if the realignment involves the type of changes to the CO that might allow for the ONT upgrade? I have an unfounded hunch that VZ has already done some realignment work at the CO because the pixellation seemed much worse in the last few days before the tech brought the LPF. Now that I've removed all inline attenuators, it's not a fair comparison anymore.


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## JasonMowry (Nov 3, 2005)

What I don't understand is why only TiVo units have this much trouble with interference from the MoCA signals. If a TiVo unit is the only consumer product that requires a low-pass filter to be on the line, then why doesn't the TiVo company provide low-pass filters to its customers upon request?


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## ciucca (Jun 29, 2004)

JasonMowry said:


> What I don't understand is why only TiVo units have this much trouble with interference from the MoCA signals. If a TiVo unit is the only consumer product that requires a low-pass filter to be on the line, then why doesn't the TiVo company provide low-pass filters to its customers upon request?


You hit it on the head. The Tivo is the issue. It has a major hardware design flaw that Tivo will not acknowledge. IMO the #1 reason why they don't is they will then have to replace 10s of thousands of S3 and TIVOHDs something a company on the brink of chapter 11 can not afford. In addition I think there is something else going on there. They probably are incapable of fixing it, or more likely unwilling to buy different tuner circuitry that works correctly, because again they cannot afford anymore cost (just MO).

Don't listen to the countless TIVOBOTs who will blast this post claiming they have proof that FIOS is causing all TIVOHD ands S3 ills. This is simply incorrect. Your only recourse is to live with it and try to use the attenuators to make it work near 90%, like I have. Do youself a favor and do not buy another TIVO product again( like me ). There is nothing better about the TIVO than the Moto DVR box except the ability to add capacity. After using the Moto I like it better than Tivos mid 90s user interface.


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## NotVeryWitty (Oct 3, 2003)

ciucca said:


> I work for Verizon


Just so everyone knows what his bias is...


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## lrhorer (Aug 31, 2003)

ciucca said:


> You hit it on the head. The Tivo is the issue. It has a major hardware design flaw that Tivo will not acknowledge.


This is nonsense. It is not a design flaw that the TiVo does not handle signals well outside it's band of interest. It *IS* a design flaw that an ONT which is supposed to deliver signals as high as 850MHz passes high levels of carriers above 1000MHz. It is not a design flaw of either unit that the two cannot be used in conjunction with each other in every environmental situation without signal treatments of some sort in some cases.



ciucca said:


> IMO the #1 reason why they don't is they will then have to replace 10s of thousands of S3 and TIVOHDs something a company on the brink of chapter 11 can not afford.


They are not on the brink of chapter 11. The statement is an out and out lie, and your credibility has dropped to zero for having made it. It was low enough to begin with, especially given your bias as a Verizon employee. Do you really want me to bring up the fact that Verizon in its former incarnation did file chapter 11 because of its massive malfeasance? Do you really want me to bring up the number of huge lies told to the public by official representatives of the company which now calls itself Verizon? You definitely don't want me bringing up my professional involvement with Verizon, which far exceeds the level of involvement of any consumer with any provider TiVo, Verizon, or otherwise, nor the level of incompetence I encounter on a daily basis within the organization. (To be fair, there are also some exceedingly competent employees at Verizon, some of whom with which I have close professional ties.)



ciucca said:


> In addition I think there is something else going on there. They probably are incapable of fixing it, or more likely unwilling to buy different tuner circuitry that works correctly, because again they cannot afford anymore cost (just MO).


The tuner is purchased off the shelf, just like every other OEM such as Motorola, Cisco, Hewlett Packard, and dozens of others. The tuners used in the Tivo are used in millions of other devices, as well. They also meet specifications laid down my the FCC and by CableLabs, so your rant is not only nonsense, it is inappropriate, as well.



ciucca said:


> Don't listen to the countless TIVOBOTs who will blast this post claiming they have proof that FIOS is causing all TIVOHD ands S3 ills. This is simply incorrect.


'No more so than your post. You have not provided any evidence that any TiVo device will function improperly with a proper and appropriate set of signals at its input. None. Provide such evidence, or shut up. Yes, in answer to your next rant, anyone suggesting it is FIOS in general or any specific FIOS installation which in and unilaterally of itself is the cause of the problem also needs to provide evidence of same, and admittedly almost none have. That is not an excuse for you to lie or to cast aspersions on TiVo or anything or anyone else.



ciucca said:


> Your only recourse is to live with it and try to use the attenuators to make it work near 90%, like I have.


What a load of crap! There is not a single recourse, no matter what. If you truly believe there is, then you are too technically incompetent to be making any suggestions to anyone. High levels can and will cause problems with Intermodulation products in any receiver, including ones costing tens of thousands of dollars. If the spectrum is comparatively flat, an attenuator will fix the problem, and is the absolute best solution for this issue. BTW, quite in contrast to your silly rant, the more sensitive a receiver is, the more expensive, and the more susceptible it is to high signal levels. If the devices of which you are so arrogantly proud are better at handling overload levels, then it is all but certain it is because they are cheaper, lower quality devices.

A more sensitive receiver is also generally speaking going to have more problems with high level out of band signals, and the specific mixer frequency is always chosen based upon the band of interest. The presence of any high level out of band signals can cause problems with any receiver. That's why the VHF band was designed with gaps in it all over the place. Modern superhetrodyne mixers can employ very high frequency mixer carriers and variable frequency carriers, but there is a limit to how high a mixer can go. It's possible the Motorola puts it's first IF way above the MOCA carrier, but it's more likely they just have a cheaper, less sensitive receiver. Post the specs for the Motorola receiver, and we'll see.



ciucca said:


> Do youself a favor and do not buy another TIVO product again( like me ). There is nothing better about the TIVO than the Moto DVR box except the ability to add capacity.


And more than 40 other features not supported by the Motorola box. The Motorola doesn't even come close. Oh, and I have done myself a favor. I've purchased a total of 5 TiVos, including 3 Series III class models. To date other than one whose Ethernet port failed outright I have not had any problem with them not either shared by other devices or fixed by software updates from Tivo. I have never experienced pixelization problems other than directly related to signal levels or source issues, and all were displayed by other devices on the system. Once every few weeks or soone channel or other will suffer a problem for a few minutes or even hours, but it's extremely rare.



ciucca said:


> After using the Moto I like it better than Tivos mid 90s user interface.


Who gives a @#[email protected] about the UI? I surely don't, especially since I rarely use it. With the TiVo, I don't need to, beyond Play, FF, Rewind, etc,. which is the same for all playback devices.


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## lrhorer (Aug 31, 2003)

JasonMowry said:


> What I don't understand is why only TiVo units have this much trouble with interference from the MoCA signals. If a TiVo unit is the only consumer product that requires a low-pass filter to be on the line, then why doesn't the TiVo company provide low-pass filters to its customers upon request?



What evidence do you have that only TiVos have the problem?
If FIOS systems are the ony ones with which the Tivo has issues, why should TiVo issue out filters?
Series III TiVos are required to meet CableLabs specs. They are not required to work with any system not certified by CableLabs. FIOS is not CableLabs certified nor does it meet CableLabs specs. Whose "fault" is the flaw?


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## JasonMowry (Nov 3, 2005)

The reason I raised the point is because of my own experience, which I believe proves my point:
http://www.tivocommunity.com/tivo-vb/showthread.php?p=6648372#post6648372
I think that the hundreds, if not thousands of posts on this forum are evidence that there is a problem. Though pixelation problems are not limited to FIOS, they seem to be much more prevalent with FIOS users. I believe that there is enough fault to go around, my dealings with Verizon have convinced me that their technical staff has been and continues to be overwhelmed and my interactions with the TiVo technical support staff has left the impression they do not care whether their units work. I still find it hard to believe that with this many dissatisfied customers no one has been forced to take responsibility for this mess, but I would settle for having at least one TiVo unit that works 100%.


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## lrhorer (Aug 31, 2003)

JasonMowry said:


> The reason I raised the point is because of my own experience, which I believe proves my point:
> http://www.tivocommunity.com/tivo-vb/showthread.php?p=6648372#post6648372
> I think that the hundreds, if not thousands of posts on this forum are evidence that there is a problem.


That wasn't my question. My question was, "What evidence do you have to support the notion that only TiVos have the problem?" More specifically, how do you know that Scientific Atlanta, Blonder Tongue, Jerrold, RCA, or for that matter even Motorola receivers don't have the same problem?



JasonMowry said:


> Though pixelation problems are not limited to FIOS, they seem to be much more prevalent with FIOS users.


Well, once again you are making a large number of unconscious and unwarranted assumptions, but even so, the fact, if it is indeed correct, that FIOS systems seem to have more problems somewhat suggests a FIOS problem, not a TiVo one.



JasonMowry said:


> I believe that there is enough fault to go around, my dealings with Verizon have convinced me that their technical staff has been and continues to be overwhelmed and my interactions with the TiVo technical support staff has left the impression they do not care whether their units work.


The functioning of any system or device within a system has nothing whatsoever to do with any human being's level of concern nor how busy they might be. Forget about whatever you "believe" or "feel" or how anyone behaves. It has nothing to do with the problem. Deal with the RF system. It's the only thing of any significance. In order to do do, you need measurements. Phone calls, speeches, and complaining posts in this forum will get you nothing.



JasonMowry said:


> I still find it hard to believe that with this many dissatisfied customers no one has been forced to take responsibility for this mess, but I would settle for having at least one TiVo unit that works 100%.


I have five which function flawlessly. (Note: no transport system is 100% error free, so occasional signal problems will occur.)

If any TiVo box fails to meet specs, then it needs to be replaced, just as any other failed device needs to be replaced. If some device in the FIOS network has a problem, then it needs to be fixed. If all the devices in the system are functioning properly, then the problem is situational, and (assuming the problem is inside the house) the homeowner or renter must see to the fix. First, however, one must determine the cause of the problem. The presence of a MOCA carrier at roughly 1200MHz could easily be part of it, especially if it is significantly higher in level than the carriers below 850MHz and especially if the overall levels are high. Triply so if there is a somewhat extreme positive tilt, as may well be the case - and properly so - for the signals at the output of the ONT.

So, to get a reasonable shot at a solution, you must be able to answer the following questions:

At the output of the ONT, what is the level of the carrier at or near

55MHz?
150 MHz?
250MHz?
450 MHz?
650 MHz?
850 MHz?
The MOCA carrier (1180MHz, if I recall)?

Then answer the same questions for the levels right behind the TiVo.

Then tell us how many feet of cable, total, are between the ONT and the TiVo.

Finally, tell us how many splitters and what sizes are between the TiVo and the ONT.


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## jedi_mike (Apr 4, 2008)

Hi, first-time poster, but I've been lurking for a little while looking for a fix for FIOS pixelation. Thanks for the tips that MoCA can be the problem. Attenuating the signal just wasn't working well for me.

I have a newer ONT that feeds both TV and MoCA signals into the house on a single coax. In my case, there are 2 frequency bands in use for data - the broadband connection from ONT to router, and the MoCA home network coming from the router. 

According to the config on the Actiontec router, the broadband data from ONT to router is at 1000MHz (I assume 1000-1050?), and the router offers a selection 6 channels for MoCA home network, ranging from 1150 to 1400MHz. Trying to narrow down possibilities, I have disabled the coax home network and even turned off the router for a while. This didn't fix the problem, so I think the ONT-to-Router broadband connection is a prime suspect for my setup.

So, armed with the assumption that the 1000MHz signal might be the culprit, I chose the Channel Master 4002IFD diplexer to use as a LPF (it offers 40db attenuation at 950-1050MHz). I'll echo bhaas' point that the Sat side of the diplexer should be capped with a terminator. Also, since I needed to leave the ONT-to-router connection undisturbed, I chose to install the LPF's at each Tivo, instead of at the ONT as others have been able to do.

I just received the diplexers a few days ago, but so far (knock wood) they are doing the trick. I've removed attenuation on both of my family's TiVO's, and still can receive all the 'problem' channels. I'll keep everyone posted on progress.

Thanks again to everone for all the suggestions. I would really have been stuck without this forum!


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## lrhorer (Aug 31, 2003)

I'm very glad you found a work-around for your situation, but people should be aware that the symptoms may have multiple causes, and a trial and error approach to troubleshooting can be maddeningly non-conclusive, especially if two or more contributing factors are present, such as would be the case with a large tilt, high levels, significant IM distortion in the ONT itself, and the presence of one or several high level MOCA carriers. Eliminating one factor may not eliminate the symptoms, and it's virtually impossible to now which effects are causative without taking measurements.

That said, it is of course easy to install a Low Pass Filter or two and then try some attenuation. You mentioned two outlets, by which I deduce there is at least 4 dB flat loss in a splitter plus perhaps a dB for the Diplexer. It's also commensurately likely that the wall drops are of significant length, perhaps 50 feet or so. That brings the loss at the high end to about 11 or 12 dB with the loss at the low end being perhaps 6 DB. Assuming the ONTs are set up with a 7 or 8 DB tilt and an output of perhaps 0 / +7 dBmV at the low / high frequencies, that puts the signal much closer to optimal than a single outlet with 30 feet of cable between the ONT and the TiVo.


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## DCIFRTHS (Jan 6, 2000)

lrhorer said:


> That wasn't my question. ...


I really enjoyed reading your last few posts. No sarcasm intended - I'm serious.


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## jedi_mike (Apr 4, 2008)

Ihorer, I agree entirely with your point that there can be multiple problems. My FIOS install has broadband and TV on the same coax line, much different from the older setups, so what works for me will not work for others. But without a means to measure, trial and error is the best I can do to troubleshoot, even though it is maddening.



lrhorer said:


> ...That brings the loss at the high end to about 11 or 12 dB with the loss at the low end being perhaps 6 DB. Assuming the ONTs are set up with a 7 or 8 DB tilt and an output of perhaps 0 / +7 dBmV at the low / high frequencies, that puts the signal much closer to optimal than a single outlet with 30 feet of cable between the ONT and the TiVo.


I think my loss is even higher. Vz installed an 8-way splitter, and the run to my upstairs Tivo is 100 feet. I didn't mention in my first post that even with this loss, I needed a mimimum of 13db additional attenuation to pick up the HD channels. There is definitely some unwanted tilt in my home, because when I ended up at the 13-16db needed for HD, some SD channels were at too low a level for the tivo to recognize at all (I'd have to check to see which channels are in which frequency bands, but I think the lowest level SD channels are under 300MHz and HD is over 500).

Long story short, I was able to replace 15db attenuation with a LPF rated at 0.8db thru loss, and for the first time I can tune a wide variety of channels. All channels I've checked show s/n over 35db and no errors. I'm not going to claim victory without going for a while with no pixelation, but I'm much closer with an LPF than I was with attenuation.


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## ciucca (Jun 29, 2004)

Thanks Irhorer you proved my point. I think you protest too much. 

One thing you miss is that the motorola box does not have a pixelation issue and the TIVO does. Why does your company continually say that the problem is not theirs? I suspect that the problem is with the low quality commercial grade QAM tuners TIVO uses (to save money no doubt). I also suspect there are only marketing types working there, and not technical people. Why doesn't your management call Motorola for help? I'm sure they will gladly license their hardware design to you for a small fee.


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## Gerhard (Sep 29, 2002)

ciucca said:


> Thanks Irhorer you proved my point. I think you protest too much.


I'm going to add my 2 cents even though no one asked for it:

I'm one of the S3 early adopters. As with any one that purchases a product when it first comes out, you invariably get screwed.

I originally had Comcast (crapcast as I like to call them), and they were OPENLY hostile about having to support CableCARDs.

No kidding, I had one rep litterly tell me how cablecards were bad, that they were forced to have to support them, and, when pressed, that they took revenue out of the pockets of Comcast. (I'm being polite here, if were we in a bar talking about this one of us would have been in the hospital, but the altercation would have been started by the Comcast guy. -He was THAT angry.)

I've never forgotten that... and all through-out my dealing with the S3 artifacting / pixelization / tiling issues I've remembered that MOST cable vendors DO NOT want to support cable cards or 3rd party DVRs because it affects their revenue stream.

Verizon has not been like Comcast has, but, to be honest, they are just as screwed up when it comes to dealing with any issues outside of the norm. They also have issues with billing and dealing with you when you are not a verizon phone customer.

However, unlike CrapCast, Verizon seems to have a decent equipment infrastructure... and while their techs are not always the most knowledgeble, they are much better then most.

The point is: Cable companies can not be trusted, as Tivo IS a competitor to them.

The REALITY is that the problem is BOTH a Verizon and TIVO issue.

Tivo functionally makes the best product out there. (Menu wise...)

...but, there has to be an issue with them when you compare them to a Motorola box... the Tivo is sensitive compared to other products, and that causes video issues.

However, I KNOW that I've got a Verizon related issue:

If I put two diplexers in line with the ONT and the Tivo S3, my RS Uncorrected and signal strength flux issues almost go away.

If I put ONE of the diplexers in line with the ONT, the problem almost goes away.

If I put ONE of the diplexers in line with the S3, there isn't much of an impact.

So that means that the 611i I've got is probably a large part of the problem...

Frankly, I don't trust that Tivo's product isn't flawed eletronically, but I know that Verizon has an issue through testing.

What really annoys me, generally, is the amount of crap you have to go through to get a fix from either vendor.

(I've called Verizon to come out an place the low-pass filters in place. I'm hoping that they are a better quality then the diplexers I'm using. In preparation for the service call I've removed the diplexers... and MAN and I getting a lot more distortion than I was before...)

Gerhard


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## exdishguy (May 1, 2004)

Sorry if this has been confirmed, but I have a ONT 612 - does this problem only manifest itself with the ONT 611? I have Fios TV scheduled for install and ordered three TiVo HDs and are trying to figure out if I should be pushing for the installer to bring attenuators or not. Thx


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## webin (Feb 13, 2008)

I don't think we can reasonably determine if it's an issue with a particular ONT model at this point. It may be that the 611 is worse off than the 612, but that certainly isn't the only problem we're working on.

I would push for the attenuators regardless, especially when the tech might give them to you for free.


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## Gerhard (Sep 29, 2002)

exdishguy said:


> Sorry if this has been confirmed, but I have a ONT 612 - does this problem only manifest itself with the ONT 611? I have Fios TV scheduled for install and ordered three TiVo HDs and are trying to figure out if I should be pushing for the installer to bring attenuators or not. Thx


There is a document floating out there where Verizon indicates that the 611 and 1000 model units have issues with MoCA feedback.

I haven't seen anything else about the other models.


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## DCIFRTHS (Jan 6, 2000)

Gerhard said:


> There is a document floating out there where Verizon indicates that the 611 and 1000 model units have issues with MoCA feedback.
> 
> I haven't seen anything else about the other models.


I posted it earlier in this thread, but there is the link for convenience.


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## exdishguy (May 1, 2004)

Thanks for the replies. I'll ask the installer to bring along attenuators and see how things go. My understanding is that I want the signal to be about 31dB at the receiver?


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## JasonMowry (Nov 3, 2005)

I'm disappointed that though it seems lrhorer might have technical knowledge to share, the tone of posts seems to be more accusatory than helpful. I listed the details of my problem in the main pixelation sticky thread, and I've already tried attenuators, removing the MoCA router, a diplexer, and replacing the TiVo unit twice and none of these has fixed the problem for me. Could anyone take the details of my case and offer another solution or diagnostic measure? (Also please keep in mind I have no professional signal diagnostic tools.)


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## cableguy763 (Oct 29, 2006)

JasonMowry said:


> I'm disappointed that though it seems lrhorer might have technical knowledge to share, the tone of posts seems to be more accusatory than helpful. I listed the details of my problem in the main pixelation sticky thread, and I've already tried attenuators, removing the MoCA router, a diplexer, and replacing the TiVo unit twice and none of these has fixed the problem for me. Could anyone take the details of my case and offer another solution or diagnostic measure? (Also please keep in mind I have no professional signal diagnostic tools.)


lrhorer is absolutely correct in his diagnosis of the problem. The 31 db above the noise floor is ridiculous. You want that number to be as high as possible. The more you attenuate, the closer you get to the noise floor. A lot of this has to do with, as lrhorer pointed out, fios is not built to cablelabs standards that the tivo is. Fios simply doesn't care about cablelabs certifications. Why should they. They don't need cablelabs approval, they don't even have to give you QAM. They can go like ATT did and deliver pure IPTV and say screw your tivo. Your elected officials gave them that right.


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## Roderigo (Mar 12, 2002)

ciucca said:


> I suspect that the problem is with the low quality commercial grade QAM tuners TIVO uses (to save money no doubt).


This statement is completely meaningless. The only thing that matters quality-wise is does the tuner meet the specifications as set out in the CableLabs specifications. That's the specification where the Cable industry has dictated to the CE industry. If it meets those specs, then something needs to be fixed on the cable side, if it doesn't meet the specs, then tivo's at fault. The cable industry, through CableLabs tests UDCPs, so if it's not meeting some requirement, it should have been called out long ago before the boxes started shipping. If the problem is something that isn't specified, then the cable industry needs to fix their requirements.

I certainly wouldn't fault tivo for using the cheapest tuner they can find *that meets the requirements imposed on them*. Whatever tuner they select - you the customer is going to have to pay for it. They pick a better tuner, and the price of the box goes up.

I also wouldn't fault a cable company for deciding to spend the extra money for a box with a "better" tuner. Up until they were required to support 3rd party equipment, it's probably cheaper for them to have more expensive tuners than more expensive (well-trained) technicians that can keep the signal within the specifications.

And, who knows if some characteristic of the tivo tuners is better than the motorola tuners. If the tivo works, but the moto boxes don't, they don't have any finger to point, and they have to resolve the problem. If it's the other way around, they're perfectly happy to "blame" the 3rd party equipment, without investigating all the possible causes of the failure that could be theirs.

And, as cableguy just pointed out, if Verizon is playing in one part of the cablelabs spec space (providing cablecards for 3rd party equipment), they also need to play by the rest of the rules to make sure the 3rd party equipment works properly.


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## lrhorer (Aug 31, 2003)

DCIFRTHS said:


> I really enjoyed reading your last few posts. No sarcasm intended - I'm serious.


Well, thank you. I hope they have been instructive to some, and interesting to all.


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## lrhorer (Aug 31, 2003)

JasonMowry said:


> I'm disappointed that though it seems lrhorer might have technical knowledge to share, the tone of posts seems to be more accusatory than helpful.


You may be right, and I apologize for that. It wasn't intentional, but I was tired and I get frustrated when misinformation is propagated over and over.



JasonMowry said:


> I listed the details of my problem in the main pixelation sticky thread, and I've already tried attenuators, removing the MoCA router, a diplexer, and replacing the TiVo unit twice and none of these has fixed the problem for me.


My point is, without measurements, one is just shooting in the dark. There is a reason why every technician carries a Signal Level Meter or Spectrum Analyzer. Troublshooting RF problems, except for certain very specific problems, is all but impossible without one.



JasonMowry said:


> Could anyone take the details of my case and offer another solution or diagnostic measure? (Also please keep in mind I have no professional signal diagnostic tools.)


You need to get levels. I realize you may not have access to an SLM or Spectrum Analyzer - they aren't cheap. Verizon, however, does. I also realize that not being a technician or engineer, it might not be instinctive for you to inquire about the RF levels when the Verizon tech comes out, but in something better than 90% of cases, measurements taken with an SLM will pinpoint the problem.

In the mean time, all you can really do is undertake a visual inspection and make sure all connectors are secure and tight. The F connectors should be lightly snugged down with a small wrench. Don't use a lot of force, but it should not be possible to unscrew the connectors with one's bare fingers. MAke sure all splitters or directional couplers are of good quality and are properly installed. A backwards DC or splitter can wreak all sorts of havoc. If you'll give us the details of the topology of the network inside your house, we can make some half-way eductaed gueses as to what might work, but without the details of the RF plumbing in your house, we're shooting blind, and are highly unlikleyto hit upon a proper solution.


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## lrhorer (Aug 31, 2003)

jedi_mike said:


> Ihorer


Please, it's lrhorer, not irhorer.



jedi_mike said:


> I think my loss is even higher. Vz installed an 8-way splitter


That's about 10.5 dB at 55 MHz and 12 - 13 dB at 850MHz.



jedi_mike said:


> , and the run to my upstairs Tivo is 100 feet.


Does that include both the cable between the ONT and the input of the spitter and the cable between the output of the splitter and the TiVo? A 100' RG-6 cable will drop about 1.5dB at 55MHz and 7.0 dB at 850 MHz. That 's a total loss of about 12 dB at 55 MHz and 20 dB at 950 MHz. If the output of the ONT has an 8 dB slope, then the input to your TiVo should be almost perfectly flat.



jedi_mike said:


> I didn't mention in my first post that even with this loss, I needed a mimimum of 13db additional attenuation to pick up the HD channels.


This suggests the output of the ONT might be greater than perhaps +35 dBmV at 850 MHz. That's pretty hot. Much higher than that will start to produce significant IM distrotion products in the output gain stage of the ONT.



jedi_mike said:


> There is definitely some unwanted tilt in my home, because when I ended up at the 13-16db needed for HD, some SD channels were at too low a level for the tivo to recognize at all (I'd have to check to see which channels are in which frequency bands, but I think the lowest level SD channels are under 300MHz and HD is over 500).


It's possible the ONT has a flat, or nearly flat output. If so, then with 100ft of cable, it would be best to have an equalizer (also called a "titlt compensator" inline with your TiVo. The closer the spectrum is to being completely flat at the back of the Tivo, the better.



jedi_mike said:


> Long story short, I was able to replace 15db attenuation with a LPF rated at 0.8db thru loss, and for the first time I can tune a wide variety of channels. All channels I've checked show s/n over 35db and no errors. I'm not going to claim victory without going for a while with no pixelation, but I'm much closer with an LPF than I was with attenuation.


Both may be appropriate, perhaps equalization, as well.


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## lrhorer (Aug 31, 2003)

Roderigo said:


> This statement is completely meaningless. The only thing that matters quality-wise is does the tuner meet the specifications as set out in the CableLabs specifications.


That's correct, but my advice is to ignore him. At first I thought he really might be a Verizon employee, but if so he's not being very prudent by announcing the fact. Indeed, it could land him in some fairly deep trouble unless he is specifically authorized to speak on behalf of Verizon. I think he's really just a troll, however, seeking to elicit emotional responses by claiming to be a Verizon employee.



Roderigo said:


> That's the specification where the Cable industry has dictated to the CE industry. If it meets those specs, then something needs to be fixed on the cable side


Well, not necessarily. First of all, it could easily be a fault in the customer's wiring or passive equipment, or amplifier if they have one. Secondly, interoperability issues are not necessarily the "fault" of either device. It can sometimes take a bit of finesse to get two boxes from different manufacturers to play nice together.

On the other hand, if the TiVo were failing regularly to meet the specs, then it would never have received certification, the possibility of a bad manufacturing run of tuners aside.



Roderigo said:


> I also wouldn't fault a cable company for deciding to spend the extra money for a box with a "better" tuner. Up until they were required to support 3rd party equipment, it's probably cheaper for them to have more expensive tuners than more expensive (well-trained) technicians that can keep the signal within the specifications.


Actually, FIOS has a bit easier time of it maintaining proper signal specs at the customer premise because they take the fiber all the way to the home.
CATV companies pass the signal through a modest amount of aluminim sheath coaxial cable - perhaps 50 or 60 dB worth, and employ 2 or 3 amplifiers along the way. That said, mantaining signal levels is not terribly difficult. The equipment has temperature compensating equalizers and automatic gain controls, and typically two simple potentiometers are tweaked in a very simple procedure to set amplifier output levels.


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## lrhorer (Aug 31, 2003)

exdishguy said:


> Thanks for the replies. I'll ask the installer to bring along attenuators and see how things go. My understanding is that I want the signal to be about 31dB at the receiver?


No. First of all, dB is not a measure of signal level. It is a measure of the ratio of two signal levels. RF levels may be variously measured in Watts, milliwatts, volts (across a fixed impedance), milivolts, or microvolts, etc. They are also frequently measured in dB relative to some refernece level. The unit dBm, for example, is a ratio of the measured signal to a reference carrier of 1 milliwatt. The unit dBmV, commonly used in CATV systems, is the ratio of the level of the measured signal to a reference of 1 millivolt across 75 ohms. For an 800 MHz spectrum like that employed by FIOS, the levels probably need to be somewhere above -20dBmv and below -10 dB mV.


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## webin (Feb 13, 2008)

I "think" I was told -17dB was ideal at the TV when I had fios installed in February.


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## Gerhard (Sep 29, 2002)

FYI:

The Verizon tech did show today and gave me two 5-860MHz low pass filters.

I put one on the Tivo and one at the ONT 611.

Interestingly, the Verizon low pass filter has a fair amount less signal drop than the diplexers I was using.

Also, the tech was well familiar with both the Tivo's sensitivites AND the ONT 611 issue. He vey carefully went though the channels I've been having issues with and then added and removed attenuators until the bad channels fell within the specs that have been listed here many times.

It appears that I had the signal over attentuated by about 6dB, so when we lowered the wost channel (747MHz, Channel 835) by only 3dB plus the low pass filter... that dropped the signal to 86-90dB... and all is good.

The diplexer plus the 9dB I had on there was dropping the signal to 58dB, which was too much. (Of course, I'm still confused as to why is was fluctuating between 58dB and 78dB...)

GB


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## Ziggy86 (Jun 23, 2004)

Keep us posted as to how it holds up.

Steven



Gerhard said:


> FYI:
> 
> The Verizon tech did show today and gave me two 5-860MHz low pass filters.
> 
> ...


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## lrhorer (Aug 31, 2003)

Gerhard said:


> FYI:
> 
> The Verizon tech did show today and gave me two 5-860MHz low pass filters.
> 
> ...


That's not particularly surprising.



Gerhard said:


> It appears that I had the signal over attentuated by about 6dB, so when we lowered the wost channel (747MHz, Channel 835) by only 3dB plus the low pass filter... that dropped the signal to 86-90dB... and all is good.


First of all, dB is not a measure of signal level. As I mentioned a couple of posts above, the unit dB is a ratio of signal levels. In particular, it is ten times the base 10 logarithm of the ratio of two power levels, or 20 times the base 10 logarithm of the ratio of two voltages, provided the referenced voltages are both developed across the same impedance. Secondly, there is nothing anywhere in the vicinity of your TiVo that comes anywhere close to 90 dB of anything. A power level of +90 dBmV is 31.6 volts or 13 1/3 watts. If that were per carrier, it would amount to more than 1700 watts for the entire RF spectrum. A room heater that plugs into a 120VAC duplex receptacle by law cannot exceed 1500 watts. The actual optimal signal level is somewhere around -20 dBmV, or 100 microvolts - about 130 trillionths of a watt - per carrier or about 20 billionths of a watt for the entire spectrum.



Gerhard said:


> The diplexer plus the 9dB I had on there was dropping the signal to 58dB, which was too much.


I assure you, the diplexer was not attenuating the signal by 30 dB, and the resultant signal was nowhere near 58 dBmV. Even the total power output at the ONT is probably not +58dBmV, although it's not completely impossible.



Gerhard said:


> (Of course, I'm still confused as to why is was fluctuating between 58dB and 78dB...)


It's highly unlikely the signal was fluctuating by 20 dB, but to answer the more fundamental question, the fluctuation is probably due to a beat product between the MOCA carrier and carriers within the band of interest.


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## webin (Feb 13, 2008)

lrhorer said:


> First of all, dB is not a measure of signal level.


It's clear he doesn't fully understand the units of measure involved.... I can't say I fully do either, but throwing out a paragraph of technical background information won't really help.

It's as simple as saying "The single level is no in dB, but rather a unitless value between 1 and 100." That would correct all the issues you have with his post.


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## lrhorer (Aug 31, 2003)

webin said:


> It's clear he doesn't fully understand the units of measure involved....


Which is why I explained them.



webin said:


> I can't say I fully do either, but throwing out a paragraph of technical background information won't really help.


There was very little technical information in the post, and nothing any high school graduate should be unable to understand.



webin said:


> It's as simple as saying "The single level is no in dB, but rather a unitless value between 1 and 100."


First of all, I believe you are inferring he is talking about the signal level indicator in the TiVo diagnostics. I rather suspected it might have been that about which he was speaking, but could not reasonably infer it for certain. Secondly, the signal indicator in the TiVo isn't a unitless value. I don't really know what it is. It might be a power level or a voltage on some arbitrary scale, or it might be an AGC bias level, but no matter what it is somehow related to the input level and as such has some unit attached to it as must all measures of physical quantities.



webin said:


> That would correct all the issues you have with his post.


But would fail to educate those, including the OP, with misapprehensions as to what a decibel is and why it is not a measure of signal level. Decibels, BTW, are unitless, but signal level measurements never are. That is why signal level measurements are never in dB, but may be in dBmV or dBm. Attenuation and amplification factors are unitless, and so are often expressed in dB. Had I made the statement you did, I would have been guilty of spreading even more misinformation. I don't mean that statement to be abrasive or derogitory, it is simply a fact.


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## Gregor (Feb 18, 2002)

I put Channel Master 4002IFD diplexers on my S3s, capping off the satellite input.

Not sure it made any difference as I am seeing some occasional pixellation. When I get pixellation, the signal strength generally varies widely (70-100).

Not sure what next to try, I always see 0 errors at the FIOS HD box diagnostics.


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## lrhorer (Aug 31, 2003)

Gregor said:


> I put Channel Master 4002IFD diplexers on my S3s, capping off the satellite input.


What do you mean, "Capping off." Simply putting a dust cover on the port doesn't accomplish anything. You must use a proper 75 Ohm terminator. Did you? If not, it's no surprise it didn't have much effect.



Gregor said:


> Not sure it made any difference as I am seeing some occasional pixellation. When I get pixellation, the signal strength generally varies widely (70-100).


While not definitive, that is certainly a likely symptom of IMD. Excessive amounts of IMD can be caused by levels that are too high, too much tilt, high level out of band carriers, or any combination of the 3.



Gregor said:


> Not sure what next to try, I always see 0 errors at the FIOS HD box diagnostics.


That doesn't particularly surprise me.


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## webin (Feb 13, 2008)

lrhorer said:


> What do you mean, "Capping off." Simply putting a dust cover on the port doesn't accomplish anything. You must use a proper 75 Ohm terminator. Did you? If not, it's no surprise it didn't have much effect.


Jesus Irhorer! Can't you just assume people are saying the right things even if they aren't being 100% succinct? He didn't say "I put a dust cover over the terminal". He didn't say "I put bubble gum over the holes." He didn't say "I soldered the terminal closed so the electrons couldn't escape." He said "I capped satellite input", which any rational person should assume means he put 75-ohm terminators on the terminals."

I don't know about everyone else around here, but I'm really getting tired of the accusatory nature of your posts. You have a lot of quality information (a lot more so than I do), and you're generally trying to help people, but you sound like the playground bully doing it.


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## ilh (Dec 21, 2007)

Since the FiOS channel realignment, I've been having terrible pixelation on CNNHD and HISTORYHD. I need to go through and check channels vs. their carrier frequency etc. to see if there is a pattern. Most of the HD channels I had previously are fine.

In any case, I tried an Eagle Aspen diplexer and properly capped off (haha) the satellite "output" with a 75-ohm terminator. It made no difference to my issues. The RS uncorrected errors are very bursty. I can watch for 30 minutes with no errors and then I can't watch at all for 2-5 minutes there are so many errors. I haven't yet correlated whether these bursts tend to happen during heavy internet usage, but who knows. I am not using MoCA, but I don't know if my ONT is configured to try to use MoCA.

I'm going to have to call Verizon to have them look into my signal issues, have them install proper low pass filters, etc. I'll make them prove to me that CNNHD and other problem channels are completely in spec. What's the best way to approach this call to Verizon? It usually feels like pulling teeth talking to the CSRs on the phone...

Well strike one. I called the support number over my lunch break, and the agent wouldn't authorize a tech visit unless I was sitting in front of the TV while he hit the CableCARDs. I should have lied and said I was in front of it and that despite his hit I was still getting pixelation on CNNHD, but it was too late. Now I have to call back in the evening. Ugh.

--Lee


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## Gregor (Feb 18, 2002)

lrhorer said:


> What do you mean, "Capping off." Simply putting a dust cover on the port doesn't accomplish anything. You must use a proper 75 Ohm terminator. Did you? If not, it's no surprise it didn't have much effect.
> 
> While not definitive, that is certainly a likely symptom of IMD. Excessive amounts of IMD can be caused by levels that are too high, too much tilt, high level out of band carriers, or any combination of the 3.
> 
> That doesn't particularly surprise me.


Yes, I used a 75 ohm terminator.

What is IMD?


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## webin (Feb 13, 2008)

"intermodulation distortion" Crystal clear, eh?

Here's the wiki on it:
http://en.wikipedia.org/wiki/Intermodulation


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## Gregor (Feb 18, 2002)

webin said:


> "intermodulation distortion" Crystal clear, eh?
> 
> Here's the wiki on it:
> http://en.wikipedia.org/wiki/Intermodulation


Thanks. I'll leave the diplexers in and the attenuators and see if that helps the issue.

My gut feeling this is something Verizon can fix, but trying to prove this to them is going to be another matter.


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## kd6icz (Jul 17, 2003)

I have a Tellabs 612 ONT and DID have issues with pixelation. I thought it was because of not enough signal. I would look in the TiVo diagnostic screen and noticed the signal would sometimes bounce from 100% down to 89%.

So a couple of weeks ago I rearranged my setup a bit. I used to have a 3 way splitter (3.5/7.0/7.0db) right beside the ONT. The two 7.0db loss outputs went stright to two Motorola QIP-2500 STB's in different rooms and the 3.5db loss went to another 3 way splitter behind the TiVo. There I had the 3.5db loss output to the Actiontec MoCA router and one of the 7.0db loss outputs to the THD and the other to a QIP-2500.

Now I have a direct cable from the ONT going to where the THD is with a single 4 way splitter. Each output on the splitter is 7.0db loss. One to the THD, one to the Actiontec router, and the other two to Motorola STB's.

So far I have not had pixelation. What this did is drop the signal loss to the TiVo HD from 11.5 db to 7.0db. I don't have any filters in the system anywhere.


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## lrhorer (Aug 31, 2003)

webin said:


> Jesus Irhorer! Can't you just assume people are saying the right things even if they aren't being 100% succinct?


Firt of all, it's lrhorer, not irhorer. Why would I assume anything? There are plenty of people who do not understand the effects of an unterminated RF line, in the 10 years I put in as an engineer in a CATV system, I saw not 1 or 2 but hundreds of cases of people attempting to terminate directional passive devices with a dust cover. I neither assumed the OP knew what he was doing nor assumed he did not. To assume he did not would have been disingenuous on my part and to assume he did would have been totally foolish. I merely asked him to clarify his statement and verify he had used a 75 ohm terminator, and not a metal or possibly even plastic dust cover.



webin said:


> He didn't say "I put a dust cover over the terminal". He didn't say "I put bubble gum over the holes." He didn't say "I soldered the terminal closed so the electrons couldn't escape." He said "I capped satellite input", which any rational person should assume means he put 75-ohm terminators on the terminals."


No, any rational person knows better than to assume anyone's actions are anythng different than stated, and if the statement in question is in any way ambiguous, then any rational person should know better than to infer anything not directly stated. I might add that it is a very human tendency to just come up with a statement out of the blue in lieu of full actual insight into an issue. That's not derogatory to anyone, but the fact is I have 10 professional technicians earnming $70,000 each working for me, and the majority of them make mistakes and mis-statements of just this sort all the time. Why should I expect more of a non-professional?



webin said:


> I don't know about everyone else around here, but I'm really getting tired of the accusatory nature of your posts. You have a lot of quality information (a lot more so than I do), and you're generally trying to help people, but you sound like the playground bully doing it.


I am not responsibe for your feelings. You are free to take my posts however you like. You are also free to dislike me personally if you so choose. You wouldn't be the first one. The fact is in no way going to induce me to make either unwarranted or arrogant assumptions concerning the technical acumen of others in the forum. I often makes mistakes, but long, hard experience has taught me never, ever, *EVER* assume anything.


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## lrhorer (Aug 31, 2003)

Gregor said:


> Yes, I used a 75 ohm terminator.
> 
> What is IMD?


Webin's link is a good one, but to simplify a bit, any time more than one carrier is present at the input of an active device such as an amplifier or a receiver, it is possible to create additional spurious carriers within the electronics of the device, and those carriers may happen to fall right inside the same region as a desirable carrier. (Indeed, modern syperheterodyne receivers make use of the effect in order to tune the signals in the first place.) In particular, the TiVo's receiver is designed to deal with a large number of digital carriers below a certain level with frequencies between 50 and 1000 MHz. IMD increases rapidly with increasing levels, and the presence of any high level carrier outside the normal band of the Tivo can produce beat products with any number of carriers throughout the spectrum. Any carrier whose level is lower than the rest will be more susceptible to interference from the distortion products, while carriers in the band at higher levels than the rest produce greater levels of spurious signals. The level of any such signals will drop as the level of the out of band carrier is reduced. What's more, the levels of such products in general will drop 2 dB for every 1 dB drop in the overall signal level. That is why attenuation and filtering both can result in a reduction of artifiacts in a spectrum. It's also why IMD is a very likely culprit of what some FIOS subscribers are reporting. One cannot infer, however, that it is the case with every FIOS subscriber's issues, and indeed without direct verification one can't even know for certain it is the problem in any of the cases.


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## ilh (Dec 21, 2007)

lhorer, I have a FiOS tech coming to my house tomorrow morning to address pixelation issues, particularly with some of the new HD channels (e.g., CNNHD at ~270MHz). Most of my previous HD channels are fine with attenuation, but they are at higher carrier frequencies.

What kind of signal levels (dBmV) should I be looking for with the tech. Obviously he should know, but I want to make sure I keep him honest. I'll also be insisting on a low pass filter. Should this be installed at the TiVo, at the ONT, or both?

I have no MoCA on my network except for the possibility of the ONT itself. My router is attached to the ONT via Cat5. The only Verizon STB I have is a DCT700, but I do not think this talks MoCA.

Any advice is greatly appreciated. I'd really like to eliminate as much of my pixelation as possible and potentially dump most of my attenuation.

Right now my coax topology is ONT -> 30ft RG6 -> 3-way splitter. Splitter to TiVo HD is about 15ft RG6, then attenuation, but I'm not sure if it is on a 3.5dB or 7dB port of the splitter. Splitter to DCT700 is about 20ft RG6. Splitter to another HDTV is about 80ft of RG59. (I should upgrade that to RG6, but it works so I've been lazy, including 4 years with DirecTV on this cable.)

My pixelation appears to be extremely bursty. 30 minutes of no errors at all and then tens of thousands of errors over a few minutes making the picture unwatchable and causing many audio dropouts. This is not the type of pixelation I saw before I started using attenuation months ago before the FiOS channel realignment.

--Lee


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## ah30k (Jan 9, 2006)

ilh said:


> Since the FiOS channel realignment, I've been having terrible pixelation on CNNHD and HISTORYHD.


I'm getting pixelation on my HD channels as well. The QAMs they switched to must be just different enough to give my TiVo trouble. I'm wondering if it is worth trying to find a LPF or if I should just throw an attenuator on the line.


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## jhimmel (Dec 27, 2002)

ah30k said:


> I'm getting pixelation on my HD channels as well. The QAMs they switched to must be just different enough to give my TiVo trouble. I'm wondering if it is worth trying to find a LPF or if I should just throw an attenuator on the line.


I have searched quite a bit for a LPF with the correct specs and have come up empty handed.

Calling Verizon and setting up (and being home for) a service call is not something I'm willing to do at this time. I have the older 611 ONT. I would love to find a source for the correct LPF.

lrhorer, any suggestions?

Jim H.


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## lrhorer (Aug 31, 2003)

ilh said:


> What kind of signal levels (dBmV) should I be looking for with the tech.


At the back of the TiVo, you shold be seeing something around -20dBmV. I've seen a number of -17dBmV, and that's probbaly fine. As im portant as the level overall is that the tilt not be too great. If the end-to-end tilt is perhaps 6 dB or less, then the tilt should not be a problem. Have him take measurements at the low end, middle, and high end. The signal probably won't be perfectly flat, but as long as it is reasonably flat and not too high, it should be OK. Write down the measurements for later reference.



ilh said:


> Obviously he should know, but I want to make sure I keep him honest. I'll also be insisting on a low pass filter. Should this be installed at the TiVo, at the ONT, or both?


It shouldn't be necessary to install two of them, and it shouldn't make much difference where inline it gets installed. Placing it at the TiVo will eliminate possible MoCA problems.



ilh said:


> I have no MoCA on my network except for the possibility of the ONT itself. My router is attached to the ONT via Cat5. The only Verizon STB I have is a DCT700, but I do not think this talks MoCA.


The advantage to placing it at the ONT, is of course the carriers are eliminated for every receiver. This can also be a disadvantage. You can always move it if it causes problems.



ilh said:


> Any advice is greatly appreciated. I'd really like to eliminate as much of my pixelation as possible and potentially dump most of my attenuation.


Attentuation won't hurt in the least, provided every carrier is above the TiVo's minimum sensitivity.



ilh said:


> Right now my coax topology is ONT -> 30ft RG6 -> 3-way splitter. Splitter to TiVo HD is about 15ft RG6, then attenuation, but I'm not sure if it is on a 3.5dB or 7dB port of the splitter.


Some manufacturers do make symmetrical 3-way splitters whose loss is about 5 dB on every leg, but most have two -7dB legs and one -3.5 dB leg. Given the short run to the TiVo, a 7dB leg should be fine.



ilh said:


> Splitter to DCT700 is about 20ft RG6. Splitter to another HDTV is about 80ft of RG59. (I should upgrade that to RG6, but it works so I've been lazy, including 4 years with DirecTV on this cable.)


The 80ft RG-59 definitely calls for the -3.5 dB leg.



ilh said:


> My pixelation appears to be extremely bursty. 30 minutes of no errors at all and then tens of thousands of errors over a few minutes making the picture unwatchable and causing many audio dropouts. This is not the type of pixelation I saw before I started using attenuation months ago before the FiOS channel realignment.


Are you seeing erorrs - corrected or otherwise - at the same time on the STB? Your problem may be due to something like ingress. Check the connectors and cables carefully.


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## lrhorer (Aug 31, 2003)

jhimmel said:


> I have searched quite a bit for a LPF with the correct specs and have come up empty handed.


The $7 Channel Master diplexers aren't a bad choice. I hven't come across any inexpensive 850MHz LPFs. Verizon obviously has a source.


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## ilh (Dec 21, 2007)

Thank you, lrhorer.

I did a full "scan" of my channels and have determined that the following carriers (MHz) seem to be responsible for all my errors: 111, 117, 123, 129, 231, 237. The 117-129 are the lowest carriers I saw, and the 231-237 are the only in the 200MHz range. 135-147 seemed OK.

Most frequencies were 37-38dB and locked at 100 signal strength, but 231MHz was showing 31-35dB and 45-100 signal strength. This is according to my TiVo HD Diagnostics page.

I did this analysis after removing the 16dB attenuators I've been using for months. 

Hopefully the low pass filter will help.

My DCT700 doesn't seem to have errors on these frequencies according to its diagnostics page. It can't show the HD channels, but it can tune the carriers.

--Lee


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## ilh (Dec 21, 2007)

No luck. The Verizon LPF does not help me.

He said all my problem channels checked out OK on his handheld analyzer. Signal strength was about +8dBmV across the board with the LPF and no attenuators, according to the tech.

My 3-way splitter is in fact 5.5dB on all three legs. My ONT is a 611.

Adding 16-20dB of attenuators might be helping, but there are definitely a substantial number of RS corrected errors, and some uncorrected errors.

The tech said he was going to bump it back to the head end. He said maybe they have some problems there. All of the channels I'm having difficulty with are new with the recent channel realignment.

--Lee


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## kealoha311 (Dec 4, 2001)

Any tips on what to say to get a tech out to install a low pass filter? I'm on the phone with a FIOS rep now and they are saying they can't do anything(supervisor says so) because it's Tivo failing. I'm pretty sure a low pass filter will help with my pixellation as when I remove the connection to the Actiontec router and add attenuators to the Tivo connection I get very rare occurrences of pixellation.


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## ljt1227 (Sep 18, 2008)

I'm new here and would love to scan through ALL the informative posts about FiOS, but I just don't have time. Can someone tell me if FiOS has an RF analog signal on it like Comcast does? I ask because I have an old Sony Series 1 TiVO that was working fine on Comcast (for non-HD Comcast channels) now cannot pick up a signal on FiOS. In the past, I split the Comcast input to bypass the set top box, ran it right to my TiVO, and picked up a decent RF signal for recording. I can't do that now, my TiVO does not see a signal at all. Nor does a plain TV hooked to the FiOS cable, it appears there is no RF analog at all.

I apologize if this sounds stupid, but it's bugging me and I could use some advice. I paid lifetime for my TiVO service and don't really want to drop it in favor of $19.99/mo for the FiOS DVR. Thanks.


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## Gregor (Feb 18, 2002)

kealoha311 said:


> Any tips on what to say to get a tech out to install a low pass filter? I'm on the phone with a FIOS rep now and they are saying they can't do anything(supervisor says so) because it's Tivo failing. I'm pretty sure a low pass filter will help with my pixellation as when I remove the connection to the Actiontec router and add attenuators to the Tivo connection I get very rare occurrences of pixellation.


Do you have a Verizon set top box? See if there are any errors on that..


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## kealoha311 (Dec 4, 2001)

Gregor said:


> Do you have a Verizon set top box? See if there are any errors on that..


Yes, I do, but I'm not seeing any macro blocking on it. Does it have a diagnostics menu like the Tivo does to see error counts?


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## webin (Feb 13, 2008)

kealoha311 said:


> Yes, I do, but I'm not seeing any macro blocking on it. Does it have a diagnostics menu like the Tivo does to see error counts?


http://www.dslreports.com/faq/15925
To enter the diagnostics menu: With your STB powered On, hit "Power, Select, Select" quickly in sequence from the front panel or remote. To exit the menu, hit "Power" to turn off the STB. The next power up will be back to normal.


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## wmcbrine (Aug 2, 2003)

ljt1227 said:


> Can someone tell me if FiOS has an RF analog signal on it like Comcast does?


RF, yes; analog, no. (Digital and analog cable are both carried over RF.) There may be some Fios service areas that still have analog service (with a handful of channels -- Fios TV has always been mostly digital), but it will all be shut down within the next few weeks.



> _I paid lifetime for my TiVO service and don't really want to drop it in favor of $19.99/mo for the FiOS DVR._


You can get a set-top box from Verizon and let the TiVo control it. Possibly you can even get one for free (the DCT700). If not, I think it's $4 a month.


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## Gregor (Feb 18, 2002)

Depending when you bought your S1, lifetime may be eligible to transfer for free. Not sure of the date though.


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## DCIFRTHS (Jan 6, 2000)

Gregor said:


> Do not taunt happy thread counts.


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## kealoha311 (Dec 4, 2001)

After a couple more phone calls I got a hold of a good Verizon employee that realized I was a new customer and could send a tech out to me right away. He came out just a little while ago and I was lucky again that I got a very good technician to come out. We talked about this issue a bit and I told him that I can pretty much remove all pixellation issues if I added 19dB of attenuation and disconnected that Actiontec router from the splitter that also goes to my Tivo. I also mentioned that a low-pass filter helped out some people because of the MoCA traffic. He agreed that it made sense so he installed a low-pass filter on the Tivo side of the splitter and ended up putting on 22dB of attenuation. And now the error counts look better than I've ever seen them before. After a few minutes on my most problematic channel I saw the uncorrected error count only go up by 1 when it would normally creep up by 1000 every few minutes. I'll have to continue monitoring a bit, but so far it looks like it has been a good fix for me.

Oh, and the tech also said that the Tivo isn't built to meet their "higher" standard. I didn't believe that, but I don't know enough to know who really is at fault.


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## lrhorer (Aug 31, 2003)

ilh said:


> No luck. The Verizon LPF does not help me.
> 
> He said all my problem channels checked out OK on his handheld analyzer. Signal strength was about +8dBmV across the board with the LPF and no attenuators, according to the tech.


That's at the back of the TiVo? Unless I am much mistaken, that is *way* too hot. If every individual carrier in a 133 carrier spectrum is precisely +8.0dBmV in amplitude, the the total signal strength is +29.2 dBmV, and I believe that is about 10 - 15 dB higher than the TiVo can handle.



ilh said:


> My 3-way splitter is in fact 5.5dB on all three legs. My ONT is a 611.


Symmetrical 3-way splitters were fairly common in the early days of CATV deployments, but they became rather scarce in the 1980s. It seems more manufacturers are once again offering them, now. With a symmetrical splitter, of course it doesn't matter which leg feeds which drop.



ilh said:


> Adding 16-20dB of attenuators might be helping, but there are definitely a substantial number of RS corrected errors, and some uncorrected errors.


If you have a +8dBmV level on essentially every carrier, then 20dB or maybe 25 dB of attenuation may definitely be in order.



ilh said:


> The tech said he was going to bump it back to the head end. He said maybe they have some problems there. All of the channels I'm having difficulty with are new with the recent channel realignment.


That may well be suggestive of a problem with a particular modulator bank, yes, but not necessarily.


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## ilh (Dec 21, 2007)

Yes, +8dBmV on every carrier I saw on his testing device, and that is with the 5.5dB 3-way splitter in use. I have since gone back to 16dB of attenuators. 20dB works on most channels but seems to make a few too weak.

The head-end folks have bumped it back and VZ will be sending another tech to my house. I'm not holding my breath that that tech will do anything useful. I think they want to try a run directly from the ONT to my TiVo.


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## mrcrlee (Sep 24, 2008)

I just wanted to add that I've been a Tivo S3 user since Dec 2006, and a FiOS user since late 2005 and had not seen this pixelation issue ever, until last week. It started on the 800-810 channels (local HD), and moved to 500-510 (local HD) when the Washington DC market had a migrated channel lineup change yesterday.

The verizon tech came out yesterday and wasn't able to fix the problem. I then researched it and found out about the actuators and low-pass filters to block the MOCA signal from going from the ActionTec router back to the ONT. I alerted him to the fix, but he was only able to locate some actuators before coming back out this evening.

We tried a bunch of different combinations but to no avail. He left recommending my ONT be replaced, even though he conceeded he'd liked to have tried the low-pass filter thing.

So I figured, eh, I'll try the fix of removing the ActionTec router from the equation. I disconnected the RG from the back of it and let things play out.

What do you know, the problem went away. I waited about 2 more hours, plugged it back in, and the problem is still (knock on wood) gone.

It's pretty clear to me that the ActionTec router issue, referenced in this post: http://www.dslreports.com/forum/r19801518-If-you-have-problems-with-FiOS-TV is causing my issue. Although I don't understand why plugging it back in doesn't yield the pixelation, I'm not going to look a gift horse in the mouth.

I will report back, but either the signal problem went away, or migrated to another channel set. I haven't gone through all the channels, and probably won't as I don't really care if channels I don't watch have or don't have a problem.

Just wanted to let all you guys know of my potential fix.

Thanks again,
-Chris


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## Gregor (Feb 18, 2002)

mrcrlee said:


> I just wanted to add that I've been a Tivo S3 user since Dec 2006, and a FiOS user since late 2005 and had not seen this pixelation issue ever, until last week. It started on the 800-810 channels (local HD), and moved to 500-510 (local HD) when the Washington DC market had a migrated channel lineup change yesterday.
> 
> The verizon tech came out yesterday and wasn't able to fix the problem. I then researched it and found out about the actuators and low-pass filters to block the MOCA signal from going from the ActionTec router back to the ONT. I alerted him to the fix, but he was only able to locate some actuators before coming back out this evening.
> 
> ...


I noticed the same migration for pixellation as well. It was in the 800 series before the channels changed and is now in the 500 series...both local HD feeds.

Makes me wonder if the feed itself is screwed up, not my network.


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## mrcrlee (Sep 24, 2008)

Here's an interesting update.

Last night, after the tech had left and I tried the unplugging-router-thing and it worked, I called Verizon to have them cancel the ticket to have replace my ONT (the tech who came out felt it might fix it). They canceled the appointment and all was ell.

So this morning I received a call from a Verizon ONT guy, he was at my house. He said 'apparently you are having problems with pixelation on some HD channels, was I supposed to do some work or did you cancel it?'. I told him the entire story, about the filter, the backfeed from the router to the 611i ONT, etc..

He was astonished that I knew about the hardware conflicts, filter etc.., and said 'sure I have a filter, I can put one on. We usually just put those on apartment building installs because of the amount of routers in one building causing conflict. how'd did you know about the filter?! do you work for Verizon?' I told him I read about it on the internet, that it is a hot topic of discussion, and lots of people are suffering from the problem. He said 'wow, amazing'.

He said he'd install one for me no problem.

*The key here is that is an ONT problem from Verizon's standpoint. There are installers/ONT technicians and inside troubleshooters. The inside troubleshooters don't have the filters or knowledge of the problem/resolution, but the ONT technicians have both the filters and knowledge of the problem/resolution.*

-Chris


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## webin (Feb 13, 2008)

mrcrlee said:


> *The key here is that is an ONT problem from Verizon's standpoint. There are installers/ONT technicians and inside troubleshooters. The inside troubleshooters don't have the filters or knowledge of the problem/resolution, but the ONT technicians have both the filters and knowledge of the problem/resolution.*


You fellers are really making me want to get one of them thar low-passers. I've configured my ONT to produce no Moca signals, but still experience light pixelation on local HD's.... maybe a LPF can still help me.

By the way, welcome to the forum mrcrlee. You've provided some pretty good information so far.


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## Ziggy86 (Jun 23, 2004)

I too have the actiontec router and am contemplating getting FiOS TV. Can you tell me how I can disconnect the router and still have everything working (even wireless). I thought this was not possible.

Thanks



mrcrlee said:


> I just wanted to add that I've been a Tivo S3 user since Dec 2006, and a FiOS user since late 2005 and had not seen this pixelation issue ever, until last week. It started on the 800-810 channels (local HD), and moved to 500-510 (local HD) when the Washington DC market had a migrated channel lineup change yesterday.
> 
> The verizon tech came out yesterday and wasn't able to fix the problem. I then researched it and found out about the actuators and low-pass filters to block the MOCA signal from going from the ActionTec router back to the ONT. I alerted him to the fix, but he was only able to locate some actuators before coming back out this evening.
> 
> ...


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## mrcrlee (Sep 24, 2008)

Hey Ziggy and Webin,

Ziggy, you actually won't have to configure the router to not be fully connected as it should be. In my case, I just unplugged the COAX cable going into the ActionTec router for 2 hours (arbitrary time period, 5 minutes may have worked as well), plugged the COAX back in, and the pixelation I was experiencing on my local HD stations disappeared.

But worse case scenario, if yours pixelated with the COAX plugged in, you could unplug the COAX and the only thing that would be affected would be the guide information on any Verizon set-top boxes in your house. The COAX being plugged into the router makes that information accessible by the Verizon set-top boxes - that is how it is distributed.

Keep in mind though, I did not see any pixelation in over 2 years of having FIOS television. Once I did, came up to speed on the possible causes and unplugged and plugged back in that cable, it went away. So it's very possible you will not have any problems.

Webin, thanks for having me. Glad to help!
-Chris


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## ilh (Dec 21, 2007)

After another tech visit, I'm still out of luck with pixelation on several "new" HD channels including CNN HD and TBS HD (bad for MLB playoffs!). Errors are bursty. I can watch an hour without pixelation and then I cannot watch for 15 minutes due to so many errors.

The tech hooks his little handheld up to the coax and says everything is in spec on the troublesome channels even when I'm seeing the RS corrected errors slowly accumulating. I don't think the bad barrage of RS uncorrected errors has hit while a tech has been present.

The 2nd tech said he doesn't like the attenuators and prefers to use a big splitter properly terminated. He switched a 3-way splitter for an 8-way to get my signal strength down from about +8dBmV to +5dBmv. He said their target is -5 to +5. I find I need 10-16dB additional attenuation to keep things a bit more stable.

I'm at a loss as to what to try next. Having a 3rd tech come out and pronounce everything fine without doing much would probably be useless. I might try a direct cable run from the ONT to my TiVo, bypassing the splitter and runs to a DCT-700 and an HDTV. Maybe my ONT is bad. The trouble is, I don't have a Verizon HD STB to see if it is suffering too. Right now they can just blame the TiVo. My DCT-700 won't tune the troublesome HD channels.

Anyone know what their handheld testers can measure? I've only seen it showing green = good and the dBmV signal strength. Presumably this would be checking for RS corrected and uncorrected errors as well?

All my previous HD channels are fine. All my problems seem to be limited to about 6 carrier frequences in the 100 and 200MHz ranges. Not all in that range are troublesome, however.

Any additional advice? I'm tempted to ask them if they can leave any kind of test hardware on my coax for an extended period (e.g., 24h) to collect error statistics, but I doubt they'd honor that request. Maybe they'll loan me an HD STB and I can check its diagnostics page.

--Lee


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## srothkin (Sep 13, 2006)

I have an ONT611. We've seen occasional bad tiling/sound loss in the last year. It happened a few times, then didn't happen for a long time, then started happening again in the last few weeks. The channels look fine when I look at them live.

I do NOT have an ActionTec router and I do not have any STBs other than the TIVO. 

Does that mean I don't need to worry about MOCA because there aren't any MOCA devices attached to the coax cabling? Or can the ONT still generate it on its own?

I tried to get Verizon to send me a filter or a tech with a filter, but the CSR and supervisor I spoke to didn't understand the issue and said there is no such thing/problem. And the supervisor said I wouldn't need to worry about MOCA if I wasn't using the ActionTec router.


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## Gerhard (Sep 29, 2002)

srothkin said:


> I have an ONT611. We've seen occasional bad tiling/sound loss in the last year. It happened a few times, then didn't happen for a long time, then started happening again in the last few weeks. The channels look fine when I look at them live.
> 
> I do NOT have an ActionTec router and I do not have any STBs other than the TIVO.
> 
> ...


You need to refer them to the Verizon Tech article that indicates Document Number 2007-00021-MDP Issue C.

I had them come out and place band pass filters on the Tivo and at the ONT.

The guy also brought a bunch of annenuators...

He was familiar with the issue and gave me no hint of trouble.


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## aldiesel (Apr 12, 2004)

I am having the same issues with only the local HD channels in the 500 range. I was wondering if this would work

http://www.solidsignal.com/prod_display.asp?PROD=PDI-SSSF&xzoom=Large#xview


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## jayteee (Mar 29, 2009)

aldiesel said:


> I am having the same issues with only the local HD channels in the 500 range. I was wondering if this would work


I don't know if it will work for you, but I can say with 100% certainty that the filter you found at solidsignal.com is the EXACT same filter that the Verizon installer installed at my 610x ONT this past Saturday for my FiOS TV install (it also matches the one pictured earlier in this thread). After reading this thread, I ordered one from solidsignal the week prior to my TV install (I've had fios data for 4 years). I installed it at my TiVo along with 12dB of attenuators and my signal levels are within the 65 to 100 range on all channels and I haven't been getting any rs uncorrected or rs corrected errors on any channels that I have checked. So there is one at the ONT and one at the TiVo thus isolating the moca signals to the internal coax only (I also have 1 stb and one vz dvr).

I don't know if I would have had errors or not without the filters, but this thread and the work you all did here is very appreciated by this new FiOS TV subscriber + TiVo HD owner!


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## Ziggy86 (Jun 23, 2004)

aldiesel said:


> I am having the same issues with only the local HD channels in the 500 range. I was wondering if this would work
> 
> http://www.solidsignal.com/prod_display.asp?PROD=PDI-SSSF&xzoom=Large#xview


Did you get the filter? If so did it work?


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## BobCamp1 (May 15, 2002)

ilh said:


> The 2nd tech said he doesn't like the attenuators and prefers to use a big splitter properly terminated. He switched a 3-way splitter for an 8-way to get my signal strength down from about +8dBmV to +5dBmv.


LOL -- where do they get these techs? There's nothing wrong with attenuators in general. Certain brands may have issues, and you have to make sure that they are rated for the power they will see.

Splitters, on the other hand, aren't as accurate.


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## mae (Dec 10, 2001)

The explanation for the use of a splitter (with proper termination on unused ports), may stem from the lack of any assurance that the attenuator (fixed barrel or variable) is linear across the 1 Ghz spectrum. While I agree it is probably a non-issue, in theory at least, a quality splitter rated as flat (as can reasonably expected) could cause less of a tilt. This effect could compound using multiple attenuators. Non-linearity might cause some frequencies to remain overloaded, or others to fall below the threshold for a signal lock.

That is, of course, theoretical, but there is some logic to it. I've never heard of it in reality, but since nothing in RF is absolute, it does kind of make sense.


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## BobCamp1 (May 15, 2002)

mae said:


> The explanation for the use of a splitter (with proper termination on unused ports), may stem from the lack of any assurance that the attenuator (fixed barrel or variable) is linear across the 1 Ghz spectrum.


Well -- if it's a bad attenuator, buy some that are decent! They are supposed to be linear across spectrum as well. There are good and bad attenuators out there.

Plus, I've seen splitters that are non-linear across frequency as well.

Maybe if I get FIOS TV in the fall, and a Tivo HD, I'll bring home my portable spectrum analyzer to analyze the signal coming out. I also have an RF network analyzer so I can measure the performance of any attenuators and splitters that Verizon may bring. But they have to give me TV service first.


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