# Yet ANOTHER OTA HD w/ HDTIVO Tuners Thread



## Philly Bill (Oct 6, 2004)

I need advice!

I have been using a little Silver Sensor with my TV. Been great. So this week I finally hook up the HD TIVO. I know from reading that the tuners in the HD TIVO aren't as great as in the TVs, but damn...

I get breakup (blocking?) on FOX almost constantly. Like FOXs signal isn't strong enough. NBC a little too, but CBS and ABC are fine.

I finally put the Silver Sensor up in my attic - get it up "higher" now - and connected it to the TIVO with a *couple brand new diplexers*.. I don't notice much difference at all.

So then I go to Radio Shack and buy a UHF antenna this afternoon. I only live *7-9 miles* from the towers. I figure putting this antenna in my attic will give me a much stronger signal than that Silver Sensor.. after all its 40" long.

http://www.radioshack.com/product/index.jsp?productId=2103088&cp=&kw=uhf+antenna&parentPage=search









You know I didn't notice a single bit of difference. In fact I brought the Silver Sensor down and hooked it to the TV tuner (bypassing the HD TIVO) to watch FOX. DAMIT!

Now I don't know what to do. Geeze I'm only *7-9.5 miles * from the towers.. what's a brotha gotta do to get a strong OTA signal to play on my HD TIVO?? I'm sure there is SOMEONE out there that can get OTA when they only live 9 miles away!

Recommendations??

I know I can run a line *WITHOUT* the diplexers.. but its a huge pain in the butt. I'd do it though if I knew it would solve the problem but I don't want to go through all that if I don't have to. Again, it seems like OTHERS are getting their channels!

Would I get better results with a different antenna? I only tried the RS figuring I could return it if it didn't work (it doesn't). If I buy one online and it doesn't work I'm stuck with it.

IWANTMY FOX!!!!


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## Dssturbo1 (Feb 23, 2005)

might need to try the antenna outside.
what signal strenght are you getting on the hr10-250 signal meter for each station.
have you checked atennaweb.org to see if the towers are all located in same general direction. and they all are uhf, none are vhf. do you have tree troubles or other home/structures, hilly terrain blocking the line of sight to your local ota towers.

are you using all RG6 cable. double check the end connectors to make sure they are tight and well crimped. did you take the time to orientate/fine tune the antenna in the attic or just put it up there.
used a straight run to see if you got crappy diplexers/splitters. alot of them are are cheap junk.

even being 9 miles from the towers there are alot of variables in ota reception.


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## merlincc (Nov 5, 2001)

Philly I feel your pain! 

After trying all the recommended solutions from the so-called experts at Best Buy and the like I stumbled upon a HDTV site for Twin Cities HDTV users. The consensus was that the experts don't know crap. 

I returned my $120 Terk and my $50 Rat Shack antennas as well as the Silver Sensor. (these were all supposed to solve my problems. I live about 10 miles from the towers.) Upon the recommendation of my fellow TC HDTV users I purchased the ChannelMaster 4221 for about $35. It does not meet the wife-factor so I cannot put it on the roof but works nicely in the attic. I have had it for 1 1/2 months now without adjusting it. Most of the signals are in the 90's. 

I recommend this little beauty to everyone.


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## newsposter (Aug 18, 2002)

Philly Bill said:


> I need advice!
> 
> I have been using a little Silver Sensor with my TV. Been great. So this week I finally hook up the HD TIVO. I know from reading that the tuners in the HD TIVO aren't as great as in the TVs, but damn...
> 
> ...


First off there's a guy only 4 miles away and gets zero on fox so dont feel bad.

Question:. have you tried temporarily running without any dipexors at all? If the signal is good then, problem 'solved'. If a direct line doesn't solve the problems then you must really be in a bad area. have you tried just moving the antenna a micron at a time? I'm far away and even single movement helped/hurt. It was a painful process but it worked for me

OTA assistance for you in philly

http://www.avsforum.com/avs-vb/showthread.php?t=620626

http://www.avsforum.com/avs-vb/showthread.php?t=182983

also higher isn't always better, just a foot difference horizontally helped tremendously for me vs moving 2-3 ft higher on another roof. Esp. with fox. heck I even get pbs in about 50% of the time now! talk about a bonus.


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## newsposter (Aug 18, 2002)

I forgot to mention that since 6 is moving back to 6, you 'may' want to futureproof by getting an antenna that can get in 6. I decided to cross that bridge when I come to it in 2009. I could always add a vhf antenna to my DB8 or even mount somewhere else.


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## chris_h (Dec 17, 2003)

I have that exact same RS antenna, on my roof about 35 miles from the towers. At 10 miles, you may be dealing with signal overload (but I would think the diplexers would help). You may want to consider investing in a variable antenuator ($10 to $12 at RS). I found it did help me with some channels, and I had to find a "sweet spot" that lets me still get in the one with a weaker signal.


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## rifleman69 (Jan 6, 2005)

Philly Bill said:


> I need advice!
> 
> I have been using a little Silver Sensor with my TV. Been great. So this week I finally hook up the HD TIVO. I know from reading that the tuners in the HD TIVO aren't as great as in the TVs, but damn...
> 
> ...


Kind of related point, I'm in Portland Oregon, about 6 or so miles from the towers. In Portland, the towers are right near each other, but as you get closer to the towers, they're actually farther apart making them harder to dial in all of the available channels. 20-30 miles out, the towers would be closer together from your antenna and it would be easier to dial in. I have trouble with OPB and FOX coming in on my HR10-250, and through the tv themselves, they're more likely to not come in at all or have severe pixellation.

What works for one person (even your neighbor) might or might not work for you. It's definitely trial and error.


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## jcricket (Sep 11, 2002)

I experience this problem too. I'm too close to the towers in Seattle. From my location they're almost 90 degrees apart (and then there's Fox, 30 miles in the distance). I get multipath interferfence which prevents reception of some channels. After much experimentation I settled on a CM4221 for NBC, ABC & CBS (all on one tower, about 3 miles away), and another antenna just for Fox (another tower, 25 miles away). I don't get PBS or WB (on a third tower, facing another direction, about 1 mile away). Oddly, I get UPN, which is on the same tower as PBS & WB.

And even with a good antenna, close location, good cabling, I sometimes get pixelation in bad weather.

This is why getting HD locals via satellite is appealing.


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## TyroneShoes (Sep 6, 2004)

One thing you know for sure is that you are close enough to not have a low signal level problem, which means that the most likely issue is multipath interference. The best assault against that is using the highest-directional antenna you can get (assuming you are picking up all from approx. the same direction) such as a 4228 or DB8. Many folks look at this from the standpoint of gain (and gain is not your problem) and mistakently think that a high-gain antenna is overkill. For gain, it is, but for multipath, it isn't. You want the narrowest lobe and best rejection of off-axis stuff there is. It just so happens that a highly-directional antenna typically also has super gain, but that can be attenuated out later on down the chain. IOW, fix the multipath problem first with the right antenna and placement, and fine-tune the signal levels with an attenuator or amp afterwards.

If you put up a 4228 at that distance, you can assume 12 dB of gain, and that might be so much to place you above the operational window of the HR10's tuner at 7 miles away. So start with an attenuator and new antenna together, preferably the variable attenuator from RatShack, placed at the input to the HR10.


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## Philly Bill (Oct 6, 2004)

Wow. Thanks for the responses. I gotta go back to work so I'll comment later. But for the record the assumption is that I live in Philly. I don't. I live in Memphis, TN. LOL.

When I came home at lunch, I turned on the TV and no channels are breaking up. I go to the HDTIVO OTA Signal Strength and I see that the bad channel (FOX) is at 80-84% - WTF??

I didn't even know how the signal meter worked.. I thought there was a 'signal' for OTA.. not for EACH channel which could be different.

Who knows? Now they're all in the 80-90 range except NBC which is in the mid-60s. I'm starting to think maybe the stations are messing around with their power.

For now it seems ok. I know you're interested (year right) so I'll keep you posted.. ROTFL!

I like the idea of running a temporary line right from the antenna, bypassing the diplexors.

I also like the idea of buying a Channel Master.

BTW, found one here for 20 bucks.  
http://www.warrenelectronics.com/antennas/4221.htm


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## newsposter (Aug 18, 2002)

Philly Bill said:


> When I came home at lunch, I turned on the TV and no channels are breaking up. I go to the HDTIVO OTA Signal Strength and I see that the bad channel (FOX) is at 80-84% - WTF??
> 
> I didn't even know how the signal meter worked.. I thought there was a 'signal' for OTA.. not for EACH channel which could be different.
> 
> ...


it's the only way to rule out diplexor problems

If you have a high signal but no pic or bad pic, I hate to say it, but try a reboot. I had NO pic on channel 6 OTA last week yet the signal was very strong (80s) and reboot cured me.

So you didn't know about the meter huh? Well that was my friend for weeks of OTA aiming. When you say you are getting 80s, are they steady? I know it's not exciting, but try sitting there a short while and watching the meter. You can also sing your favorite song with the tone if you wish. If it's relatively steady, then you can probably rule out some things.


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## Philly Bill (Oct 6, 2004)

After posting that last message I checked again and the signal on my local FOX (the one I'm having the biggest problem with) was back to what it was before.. fluxuating between 10 and 45.... quickly... and get this.. on only the bottom meter (antenna 2?).. the top meter (antenna1?) was nothing.

This is what it did before.

Then right before leaving back for work.. it was back to the 80's.. on both antennas.. WTF?

I don't get it. Maybe its a station issue.. All the other channels show up fine. Some higher than others.. but all on antenna 1 & 2.

This sucks.


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## TyroneShoes (Sep 6, 2004)

It's doubtful that its a station issue (stations usually maintain the same power 98-99% of the time, and power reductions only affect fringe viewers for ATSC). More likely a multipath issue. A low reading does not mean low signal, just low quality of reception integrity, which can be low even when signal is high if there is interference.

As close as you are an FM trap might be something (easy) to try, also. Sometimes a third-order beat product can fall directly in the middle of a particular channel, and thwart reception. An FM trap can eliminate that happening in the tuner front end. I got an extra 3 points on certain channels when I added a trap.

Again, that is proof that the signal quality reading has little to do with station power. Did the channel's power magically go up just because I added a trap? Certainly not. But the reading did, because I was corrupting fewer bits after removing the interfering carrier(s).

This is also another reason (other than exceptional directionality) why if you have no channels lower than about 10 a 4228 works as well as it does, as it naturally filters out FM, and if the FM carriers are relatively stronger than the UHF stations, this will bring them down in relative level so they don't swamp the tuner, or the preamp, if you have one.


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## Philly Bill (Oct 6, 2004)

Wow. Thanks for the lesson shoes. 

I'm out of town today and tommorrow. but I'll certainly try the new antenna and especially the antennuator. quick and easy thing to try.

I have noticed yesterday that just moving the antenna slightly.. VERY slightly... seems to allow the 'bad' station to come in while lowering the 'signal' level on the others. I can see this is a deal with a lot of playing around til you get it to work.

Thanks for the input!

Bill


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## TyroneShoes (Sep 6, 2004)

Semper Fi, Bill.

And I think it might be good advice to anyone to get a RatShack variable attenuator and a FM trap. These are two tools that are cheap, and easy to employ, and they can tell you a lot about what's going on level-wise and interference-wise. Plus they really can't hurt reception (unless you really use them in an obviously wrong-headed manner).

A directional antenna is the best tool, though, even though that implies greater expense and a little work. But I would recommend anyone to get the trap and attenuator early on in the process, and simply take them back for refund if they don't help, after all of the fine-tuning is done.


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## JimSpence (Sep 19, 2001)

Are you sure that all of your digital stations are using UHF? If not, then you need a VHF antenna. Also, the stations digital and analog power outputs may not be the same.


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## newsposter (Aug 18, 2002)

looks like they are all uhf

```
WMC-DT	5.1	NBC	MEMPHIS	TN		59°	17.6	52
*	red - uhf	WHBQ-DT	13.1	FOX	MEMPHIS	TN		80°	11.6	53
*	red - uhf	WPTY-DT	24.1	ABC	MEMPHIS	TN		59°	17.6	25
*	red - uhf	WLMT-DT	30.1	UPN	MEMPHIS	TN		59°	17.6	31
*	red - uhf	WREG-DT	3.1	CBS	MEMPHIS	TN		79°	12.4	28
*	red - uhf	WKNO-DT	10.1	PBS	MEMPHIS	TN		87°	12.8	29
*	red - uhf	WPXX-DT	50.1	i	MEMPHIS	TN		71°	13.9	51
*	violet - uhf	KVTJ-DT	49.1	IND	JONESBORO	AR	TBD	319°	41.2	49
```


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## Philly Bill (Oct 6, 2004)

Yep. As showned by np, all UHF. I've been out of town this weekend.. I'm gonna mess with this this week.

The new antenna should be in this week too. A rotor would be nice to change the direction but that doesn't help for TIVOing. lol.

I'll get it to get a resonable signal quality on all networks (not all, just the network feeds) if it kills me. In the meantime I'll go up in the attic and move the antenna a bit when I want something off fox.. lol


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## rlj5242 (Dec 20, 2000)

Have you checked out the Memphis thread at AVS? There are a lot of guys living about the same distance as you from the towers and have already gone through the problems you are having.

The antenna you posted in your first message is the attic antenna that works best in Southaven (about 20 miles from the towers). A few guys have it working and I just need to install mine.

-Robert


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## Philly Bill (Oct 6, 2004)

Yeah, i've read. Great thread thanks. 

The Antennuator is my next step..... maybe on the way home.


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## Mr. Bill (Jan 18, 2006)

Dollars to donuts this is your issue... at least it has been *the* issue with the 4 people I have run into with exaclty what you are describing, including my own former home.

Your anntenna is in your attic. On the roof of your house you have whirlybird vents. These vents are near your anntenna. When the wind blows, the whirlybirds move and multipath the hell out of the signal. When it's calm, you get your 80% signal, perfect picture.

Check it out and tie the ones down with string to stop them spinning. If it's only one or two, it will not drastically affect attic ventilation.

Good luck!


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## newsposter (Aug 18, 2002)

Wow I never thought of a fan problem. My antenna is outside but about 25 ft from a thru the roof fan. Hope that doesn't pose a problem come summer


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## Mr. Bill (Jan 18, 2006)

newsposter said:


> Wow I never thought of a fan problem. My antenna is outside but about 25 ft from a thru the roof fan. Hope that doesn't pose a problem come summer


Is it a power fan, or does the wind only blow there in the summer?! 

Actually, you should be OK... 

This multipath issue is cause by a whirlybird being above and near the antenna (which is below it, in the attic). In other words, the whirlybird is directly in that wide signal path between the towers and the antenna.


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## Philly Bill (Oct 6, 2004)

Mr. Bill said:


> Dollars to donuts this is your issue... at least it has been *the* issue with the 4 people I have run into with exaclty what you are describing, including my own former home.
> 
> Your anntenna is in your attic. On the roof of your house you have whirlybird vents. These vents are near your anntenna. When the wind blows, the whirlybirds move and multipath the hell out of the signal. When it's calm, you get your 80% signal, perfect picture.
> 
> ...


LMAO!!!!!























I have a whirlybird fan RIGHT ABOVE the antenna! What a riot!

I don't know how that causes multpath issues.. I don't know anything about this sort of thing... but hell, you nailed whats there. I'll jam that one up and see what happens.. 

Report back in a day or so..


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## dogdoctor (Feb 20, 2006)

Philly Bill - Forgive me as I don't want to hijack this thread and have no intention of doing, so but I am running into a similar but different problem and the people responding you to know alot about the antennas and the loss of a single channel from reception.

Pertinent Info: tv kdf50we655, terk HDTVi, all local channel at 161 degrees and ~ 17 miles from the towers - area code 95831

I had/have a terk HDTVi indoor hooked up to the for approx 1.5 years and have had great reception TV. Pulled in CBS, ABC, WB, Fox, NBC - with NBC being the fussiest esp. with poor weather - winds and rain. I figured I would finally get the HR10 and an outdoor antenna - had to be better, more consistent reception than indoor, right? I went against my better judgement and paid D* to put an OTA up - wire mesh with double metal x crosses in front of the mesh.

Well today the guy sets up the antenna - diplexes it in - hooks it up to the HR10 and lo and behold signal meter in the 92's for CBS (25), but ABC (61) is pulling a big fat 0, nada, zippo.  Remainder of channels seems fine in signal strength. The service guy says that in the Sacramento area - having lots of problems with ABC. Really? I reply - turn on the TV, switch to the indoor antenna and there is ABC loud and clear.

I eventually hook the indoor up to the HR10 and ABC registers 90/91, and all the other channels are above 87. What gives? I tried combining the antenna signals with a converter - ABC now comes in at 23/24 and all other in low 30-40's.

Thankfully the indoor antenna works just fine - but what is up with the D* antenna and ABC. Any ideas, thoughts, solutions? As of now I have an ugly as sin antenna on the roof - contributing nothing but ugliness to it's existence. D* says it mine to keep in all it unfulfilling glory. Thanks D*, and here is to my own lack of better judgment.


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## newsposter (Aug 18, 2002)

Mr. Bill said:


> Is it a power fan, or does the wind only blow there in the summer?!
> 
> .


controlled by a thermostat and is powered...actually thanks for reminding me..it got slightly out of alignment last year and was 'ticking'. the clearance is so tight (replacement from home depot) that you can barely put a screwdriver blade in there.


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## poppagene (Dec 29, 2001)

Philly Bill said:


> I need advice!
> 
> I have been using a little Silver Sensor with my TV. Been great. So this week I finally hook up the HD TIVO. I know from reading that the tuners in the HD TIVO aren't as great as in the TVs, but damn...
> 
> ...


I solved my problems with a fluctuating signal strength by opening the box and connecting the feed from the rooftop antenna directly to the 2 atsc tuners inside the hr10-250.


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## Philly Bill (Oct 6, 2004)

poppagene said:


> I solved my problems with a fluctuating signal strength by opening the box and connecting the feed from the rooftop antenna directly to the 2 atsc tuners inside the hr10-250.


Hmm. How do you do that? I've never looked at the inside. Is soldering required?

Pics?

BTW, I stuck a broomstick in the fan to stop it for a test. The signal on ABC went from fluctuating between 10 and 70 to steady 80 or so. :up:

Still not perfect, but then took the antenna off the mast to move it out from under the fan and let the fan spin again. I just SET it on some suitcases, but its not 'level'... the signals got much better. Tonight or tommorrow or Saturday I'll mount it again.. level.. AWAY from the stupid whirlybird fan....


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## newsposter (Aug 18, 2002)

I wonder if the hdtv antenna primer mentions fans like this...hmmm


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## poppagene (Dec 29, 2001)

Philly Bill said:


> Hmm. How do you do that? I've never looked at the inside. Is soldering required?


No soldering required. Once you open the unit, on the inside on the other side of where the ota feed plugs in there is something kind of like a splitter with two cables coming out of it. These cables attach to the ATSC tuners on the inside with a standard F-connector connection. I used a tork wrench to open up the box and used a radioshack splitter to give me two ota feeds to plug into the 2 atsc tuners inside of the HR10-250.


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## Philly Bill (Oct 6, 2004)

poppagene said:


> ...used a radioshack splitter to give me two ota feeds to plug into the 2 atsc tuners inside of the HR10-250.


Isn't this the same thing the TIVO is doing?


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## poppagene (Dec 29, 2001)

Philly Bill said:


> Isn't this the same thing the TIVO is doing?


from another thread:

The HR10 does not have a "splitter" in the term generally understood, which would be a passive hybrid-type power divider, which is commonly referred to as an RF splitter. The HR10 contains an active unit that reamplifies a single input signal and distributes it into two output paths. It is more akin to a distribution amplifier and may provide additional active selectivity prior to each demodulator front end, and maybe even heterodyne conversion as part of demodulation. IOW, the two outputs may not be identical while on non-identical channels, and one output should be buffered from the other preventing unwanted interaction. While it performs a similar type of task, that makes it technically very different from a hybrid splitter.

http://www.tivocommunity.com/tivo-vb/showthread.php?p=3697303


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## Philly Bill (Oct 6, 2004)

This is interesting.

So how about doing what you did, and drilling another hole in the back of the case to put in one of those thingies that is in a coax wall plate? So there are two inputs.. but on the outside?

Or is that what you did? How did you run the second antenna input into it?



poppagene said:


> from another thread:
> 
> The HR10 does not have a "splitter" in the term generally understood, which would be a passive hybrid-type power divider, which is commonly referred to as an RF splitter. The HR10 contains an active unit that reamplifies a single input signal and distributes it into two output paths. It is more akin to a distribution amplifier and may provide additional active selectivity prior to each demodulator front end, and maybe even heterodyne conversion as part of demodulation. IOW, the two outputs may not be identical while on non-identical channels, and one output should be buffered from the other preventing unwanted interaction. While it performs a similar type of task, that makes it technically very different from a hybrid splitter.
> 
> http://www.tivocommunity.com/tivo-vb/showthread.php?p=3697303


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## Philly Bill (Oct 6, 2004)

newsposter said:


> I wonder if the hdtv antenna primer mentions fans like this...hmmm


I don't know.. but I've never seen it mentioed before... and it DEFINITELY made a difference.

If Mr. Bill hadn't read this thread and made that comment I'd never have thought of that.

Mr. Bill Rocks! :up:


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## poppagene (Dec 29, 2001)

Philly Bill said:


> This is interesting.
> 
> So how about doing what you did, and drilling another hole in the back of the case to put in one of those thingies that is in a coax wall plate? So there are two inputs.. but on the outside?
> 
> Or is that what you did? How did you run the second antenna input into it?


I fed an RG6 cable without an F connector through a vent hole on the bottom. After feeding it through, I stripped the end and added in an F connector. I attached this to a two way splitter and ran RG6 cable from the 2 ends of the splitter to the coaxial ports on the ATSC tuners. I completely bypassed the OTA connection on the back of the HR10-250.

I've still got 6 months on the warranty so I'm not ready to drill a hole in the case yet.


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## hhh222 (Jul 28, 2005)

poppagene

Thanks for sharing this. I just hooked one of my HD-Tivo's up using this method and...so far...it really seems to improve things. I have 2 HD-Tivos and had to use a different antenna on each to pick up all OTA's. Right now I'm getting all OTA's with one antenna on the modded unit. We'll see if this keeps up. Thanks.


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## puddyhog (Feb 11, 2006)

AWESOME!!! I have been fighting w/ ABC outside of Kansas City for the last 6 months- they refuse to give me a waiver, even though the channel (9.1 - Digital 7 - VHF) is pixelated ~75% of the time. I just hooked up my HR 10-250 OTA using the method described above, and it NOW WORKS LIKE A CHAMP!!! Too bad Sunday Night Football will not be around for another 6 months...


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## tbb1226 (Sep 16, 2004)

poppagene said:


> I solved my problems with a fluctuating signal strength by opening the box and connecting the feed from the rooftop antenna directly to the 2 atsc tuners inside the hr10-250.


Does anyone have a technical explanation for why this ought to work?

I'm in a similar spot to Philly Bill, in that I'm fairly close to the transmitters, but can't seem to get solid reception on all channels. I have been trying to deal with intermittent multipath interference on one OTA channel for almost two years, mostly by all of the other suggestions that were mentioned earlier in this thread. I've switched to the CM4221, moved it outdoors, eliminated diplexers, and even raised it 15 feet off my roof. Still, this one station has been giving me fits - sometimes working fine for weeks, and other times not coming in at all. Attenuators and FM traps have no effect for my situation, and there are no "whirlybird fans" hovering over my rooftop (not since I surrendered and released the hostages, that is )

Though I'm hesitant to crack open the box, I might try this suggestion, if only I had some explanation for what "problem" I would be solving by doing so. I guess it's just the engineer in me - I need to know how things work before messing with them.


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## newsposter (Aug 18, 2002)

tbb have you moved the antenna horizontally as well? In my case I was shooting through a 'tunnel' and moving left and right got me a perfectly stable signal which even 5ft higher couldn't match. I paid someone $400 for about 5-6 hours of work on my roof trying to find a good signal. It was that difficult. But horizontally made all the difference in my specific case.


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## tbb1226 (Sep 16, 2004)

I've considered it, but given the intermittent nature of the interference, I'm really hesitant to move it based on the specific conditions at an arbitrary point in time.

To move it, I'd have to remove it from the chimney mount and put it on a tripod or some other structure that will require punching more holes in my roof.


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## Mr. Bill (Jan 18, 2006)

Philly Bill said:


> I don't know.. but I've never seen it mentioed before... and it DEFINITELY made a difference.
> 
> If Mr. Bill hadn't read this thread and made that comment I'd never have thought of that.
> 
> Mr. Bill Rocks! :up:


"Bill's" stick together~!

Glad you are up and going again!! :up:


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## TyroneShoes (Sep 6, 2004)

tbb1226 said:


> Does anyone have a technical explanation for why this ought to work?...


 I can take an educated guess.

When I opened my HR10 for a Weaknees upgrade last year I found a module with two outputs and one input. In my case there was no way to tell if this module was a signal splitter, because on my model the outputs were coax terminated in RCA plugs. Sometimes RCA plugs are used for RF internal to STBs and the like, but more often than not, RCA connectors are only used if the signal has been converted to an IF frequency or to a baseband frequency. So my findings posted earlier reflect that. I wasn't wrong, but with the information I had there was no way to tell if the unit did frequency conversion or not, and it appeared that it most probably did.

The recent experiments done on boxes that use F-type connectors on those two output cables have shown that there is no frequency conversion in that mocule, otherwise bypassing it would not work at all, and it does.

So with this new information, what we know for sure is that the module is designed to output the same thing it inputs (with some possible wide-band filtering, but probably not) and that it is probably an active wide-band RF distribution amplifier, designed to simply add enough amplification to overcome the split loss of feeding two tuners with one downlead. We also know from previous experience, that the HR10 does not have the greatest tuner system out there, in fact it is typically inferior to your garden-variety HDTVs circa 2004-6.

Moving into the realm of pure speculation, and based on the experiments poppagene and others have done, maybe the tuners themselves are just fine, and maybe the wideband RF amp is the culprit. That would make the HR10's sensitivity to high signals make sense, for instance if the wb RF amp is overcompensating for the signal-split loss with too much preamplification. It could also explain why the HR10 is so sensitive to multipath (reflections in the wb RF amp can contribute to the aggregate reflections of multipath) and this also might explain why one tuner shows a difference in SQ reading than the other.

My theory is that reflections internal to this unit can be the only cause. If you have a clean, uninterfered signal to begin with, even if one side of the wb RF amp is adding reflections, both are still well over the threshold and both will give the same reading even though one enjoys less reflections than the other, while if you are on the edge, the added reflections in the wb RF amp contribute to lower readings on that side. That is all purely speculation, but it also makes perfect sense.

The moral of the story is that we can use this "different readings" condition to indicate that we have marginal multipath, and attack it and level issues with better antennae, better antenna placement, and proper aiming, attenuation, amplification, and filtering. And for HR10s that have F-connectors inside instead of RCA's like my unit does, it becomes very simple to bypass the wb RF amp if necessary, which is one more powerful tool for us.


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## TyroneShoes (Sep 6, 2004)

tbb1226 said:


> ...I'm in a similar spot to Philly Bill, in that I'm fairly close to the transmitters, but can't seem to get solid reception on all channels...Attenuators and FM traps have no effect for my situation...
> 
> Though I'm hesitant to crack open the box, I might try this suggestion, if only I had some explanation for what "problem" I would be solving by doing so. I guess it's just the engineer in me - I need to know how things work before messing with them.


Understandable, and I think there is little risk in the poppagene bypass method (he should get credit for that ). In your particular situation, though, being close might not be enough. I noticed that you didn't mention an amp, and when you are close it seems like probably not an issue, but it can be. I was only 12 miles away, and had issues with 2 stations. It turns out they were both using minimum power, as many stations are wont to do before analog cutoff just to save on the electric bill (which is substantial). An amp helped me, and it might help you, but you have to make sure you don't amplify too much for the strong channels (use a variable attenuator after the amp).

That would be the recommended step before cracking the box, but desperate times call for desperate measures, and like I say, the risk is probably low if you are careful and know what you are doing, and its reversible. If you have RCAs like my unit did you might have to invest in some RCA-to-F adapters. If that doesn't work then that might mean that the "RCA" units use a different type of moudule than the "F" units do.

*WARNING:* The chief caveat of opening the box is the flexible control strip connecting to the front-panel. If that is partially disengaged, you can fry the Tivo permanently (more on the Weaknees site). Make sure you always push that back in firmly before powering up. Remember, if low signal is an issue, using this bypass method will present 3.5 dB less signal to each tuner due to the splitter loss, which makes an amp even more important in marginal situations.


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## poppagene (Dec 29, 2001)

TyroneShoes said:


> I can take an educated guess.
> 
> And for HR10s that have F-connectors inside instead of RCA's like my unit does, it becomes very simple to bypass the wb RF amp if necessary, which is one more powerful tool for us.


My HR10 has RCA connectors at the web RF amp side and F connectors on the ATSC tuners.

I'm about 3.5 miles away from most of the digital stations and I have a well aimed 
Radio Shack VU-190 XR 160" Long Dual Boom, 57-Element Antenna so weak initial signal is not a problem -- which is what led me to open the box in the first place.


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## TyroneShoes (Sep 6, 2004)

First, much kudos to you for discovering this option :up:. This could help a lot of folks.

But why it works for you might be a simple as the fact that using an external passive hybrid splitter presents less signal to each tuner than using the amplified splitter built in to the HR10. IOW, you have effectively just added an attenuator, but in a somewhat roundabout way. It could be that just an external attenuator would benefit someone this close to the towers as much or more than bypassing the wb RF distribution amp module might, especially using that hot of an antenna. I would have to say that anyone thinking about trying this should try a variable attenuator first.


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## newsposter (Aug 18, 2002)

tbb1226 said:


> I've considered it, but given the intermittent nature of the interference, I'm really hesitant to move it based on the specific conditions at an arbitrary point in time.
> 
> To move it, I'd have to remove it from the chimney mount and put it on a tripod or some other structure that will require punching more holes in my roof.


I feel your pain. I told him to do a chimney mount and he did. Well it was fine for 24 hours then poof...went bad in winds.

he then put a tripod mount on, walked the length of the roof 100x different places, almost centimeter by centimeter at times...and voila...all is well and we have had SEVERE winds the past month or so. So i'm very happy and it was money well spent.


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## tbb1226 (Sep 16, 2004)

TyroneShoes said:


> I noticed that you didn't mention an amp, and when you are close it seems like probably not an issue, but it can be. I was only 12 miles away, and had issues with 2 stations. It turns out they were both using minimum power, as many stations are wont to do before analog cutoff just to save on the electric bill (which is substantial). An amp helped me, and it might help you, but you have to make sure you don't amplify too much for the strong channels (use a variable attenuator after the amp).


I've been told that all the Detroit DT transmitters are running at "full" power (whatever that means), and they are all less than 10 miles from me. I'm pretty sure amplifying the antenna signal isn't what I need.

You have convinced me that there's hope for this other fix, though. When I get some empty time in the ToDo list on my TiVo that overlaps with time I am actually home, I'll give it a try.

Thanks.


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## paulstefano (Jan 12, 2006)

Can somebody offer some advice please? 

I am in Baltimore (well actually 6 miles from the HD towers) and over the weekend, I hooked up an OTA antenna. I can get 4 out of 5 networks, and the 5th even comes in intermittedly, but constantly drops out. 

Here's what I did. 

I bought a Zenith Silver Sensor and hooked the antenna up in the living room. With the included coaxial cable and the antenna sitting on my entertainment center, I could tune in CBS clearly, and ABC off and on. This was in the evening.

Then during the day, the signal started crapping out, so I moved the antenna to a longer coaxial cable I had and into the living room, facing the antennas. Now I could get ABC, FOX, NBC, and CBS , but intermittedly. If I repositioned, I could get CBS clearly, but one or more of the other networks would lose signal.

Then, I disconnected my silver sensor, and ran a wire from my old rooftop antenna, (which is actually in my attic). I don't know the brand, it came with the house, and has to be like 20 years old. I never expected to even use it. 

With this current setup, I get NBC, FOX, ABC, the WB all crystal clear. But, CBS, keeps losing signal. 

So, I'm at a loss. What else can I do. What's causing the problem? Is it the antenna? Length of the cable? Why are 4 networks clear and 1 poor? 

I know in the area, CBS, NBC, and ABC all use the same tower. Less than 1 mile away, FOX has their own tower, about 50 feet taller. I am less than 7 miles from both towers.

Thanks in advance for you help.

paul


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## paulstefano (Jan 12, 2006)

Originally Posted by poppagene said:


> ...used a radioshack splitter to give me two ota feeds to plug into the 2 atsc tuners inside of the HR10-250.


Question, what kind of splitter. I tried this with a regular RF splitter but after 48 hours of fiddling, I couldn't process the connection anymore in my brain.

Which end (IN or OUT) gets the antenna feed, and which end go's to the receiver?

I know it should be simple, but all this thinking is hurting my brain!

thanks,.


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## newsposter (Aug 18, 2002)

paulstefano said:


> Question, what kind of splitter. I tried this with a regular RF splitter but after 48 hours of fiddling, I couldn't process the connection anymore in my brain.
> 
> Which end (IN or OUT) gets the antenna feed, and which end go's to the receiver?
> 
> ...


Except for losing some signal, a regular spitter should work fine

antenna ---- INPUT---- OUTPUT to 2 receiver inputs


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## paulstefano (Jan 12, 2006)

newsposter said:


> Except for losing some signal, a regular spitter should work fine
> 
> antenna ---- INPUT---- OUTPUT to 2 receiver inputs


Actually, I'm trying to put 2 antenna INPUTS to 1 receiver, to pick up 2 different towers.


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## newsposter (Aug 18, 2002)

paul that does sound perplexing

maybe try this antenna thread

http://www.avsforum.com/avs-vb/showthread.php?t=517400


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## newsposter (Aug 18, 2002)

paulstefano said:


> Actually, I'm trying to put 2 antenna INPUTS to 1 receiver, to pick up 2 different towers.


Ah ok, I've heard it 'may' be able to be done but I think the only guaranteed solution to prevent interference is a jointenna

http://www.warrenelectronics.com/Antennas/joiners.htm

someone else will have to confirm this


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## poppagene (Dec 29, 2001)

newsposter said:


> Ah ok, I've heard it 'may' be able to be done but I think the only guaranteed solution to prevent interference is a jointenna
> 
> http://www.warrenelectronics.com/Antennas/joiners.htm
> 
> someone else will have to confirm this


The jointenna is the way to go if you're trying to combine two different antennas.


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## paulstefano (Jan 12, 2006)

So wiring 1 antennas to an RF splitter is not helping my cause at all? Sounds like I may actually be making things worse.


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## Redux (Oct 19, 2004)

paulstefano said:


> So wiring 1 antennas to an RF splitter is not helping my cause at all? Sounds like I may actually be making things worse.


I take it you meant "2" antennas.

I think a splitter in reverse is always worth trying first, it's cheap and sometimes works, but since it frequently introduces more multipath and/or overload you usually have to go to a Join-tenna or more sophisticated solution. The join-tenna on the one hand passes only your channel from the specialty antenna and on the other punches a hole for it in the feed from your regular antenna.


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## paulstefano (Jan 12, 2006)

Redux said:


> I take it you meant "2" antennas.
> 
> I think a splitter in reverse is always worth trying first, it's cheap and sometimes works, but since it frequently introduces more multipath and/or overload you usually have to go to a Join-tenna or more sophisticated solution. The join-tenna on the one hand passes only your channel from the specialty antenna and on the other punches a hole for it in the feed from your regular antenna.


I did mean "2". As of now, I have the 2 antennas wired to a splitter, then into the receiver. I have the same reception issues I have by using just either one of the antennas by themselves.


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## Mark W (Dec 6, 2001)

Can a jointenna be placed outside at the antenna location, or does it need to be inside?


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## paulstefano (Jan 12, 2006)

Whoa! Stop the presses! After sniffing around the AVS forum, as somebody suggested in this thread, I completely solved my problem. 

It turns out the signal was too STRONG! As I mentioned, I'm only 6 miles from the towers. I read that CBS has the lowest frequency in Baltimore, so it broadcasts with the most power. I picked up an attenuator from Radio Shack and put it on the antenna line. BINGO! Problem solved! I now get a solid 77% signal on CBS and all the other networks remain strong and clear! 

All the aiming in the world was not going to solve that problem. My poor receiver was being overpowered by the strong signal. 

If you are close to your towers, and have signal dropping in and out, try an attenuator. I paid $9.99 for the adjustable one. You can get a single power -6db one for about $4. 

This saved my hundreds of dollars in antenna costs, and countless hours of wasted time trying to aim an antenna that was already perfectly tuned!


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## newsposter (Aug 18, 2002)

You just took food out of an installer's kids mouths


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## A J Ricaud (Jun 25, 2002)

Mark W said:


> Can a jointenna be placed outside at the antenna location, or does it need to be inside?


The jointenna goes outside on the antenna mast.


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## Redux (Oct 19, 2004)

Mark W said:


> Can a jointenna be placed outside at the antenna location, or does it need to be inside?


Either way. It comes with mast-mounting hardware and I think it has screw mounting holes for attaching to a wall (I don't remember for sure). Obviously if both antennas are mast-mounted you save the second downlead by using the mast-mount for the join-tenna, but if your single-channel is so strong you're using an inside antenna, you can join them at the set or wherever.


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## tbb1226 (Sep 16, 2004)

tbb1226 said:


> I've been told that all the Detroit DT transmitters are running at "full" power (whatever that means), and they are all less than 10 miles from me. I'm pretty sure amplifying the antenna signal isn't what I need.
> 
> You have convinced me that there's hope for this other fix, though. When I get some empty time in the ToDo list on my TiVo that overlaps with time I am actually home, I'll give it a try.


Finally got around to trying the internal antenna splitter bypass. No dice.


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