# Do high SNR levels on Verizon FiOS affect Roamio Picture Quality



## leepoffaith (Apr 21, 2014)

I'm having a problem with a few stations being pixelated here and there. Cinamax is one of them. The DVR diagnostic page shows all the stations have a 39 - 40 SNR with 97-100% quality. Most of the other stations are ridiculously clear and this only seems to affect a few. From the other posts I've read this has to do with the cable card model # (I have the newest one) and that was fixed with a software update. Do I still need to attenuate the SNR lower? If so, what level seems to work for everyone?

Also, if anyone has any extra of these lying around they don't need I'd be more then happy to take them off your hands. 

Thanks in advance for the help.

~Lee


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## lgnad (Feb 14, 2013)

there are definitely other posts on here from FIOS users having too high a signal level causing issues and needing to put an attenuator on the wire...


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## leepoffaith (Apr 21, 2014)

lgnad said:


> there are definitely other posts on here from FIOS users having too high a signal level causing issues and needing to put an attenuator on the wire...


Yeah, I read those which is why I'm double checking. I thought that issue was solved with the new cablecard and software update, but I could have been mistaken. Before I go out and buy one I'd like to know for sure if possible.


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## aaronwt (Jan 31, 2002)

I'm on FiOS but the highest I have seen is a 38 SNR. But my channels have been fine. They range between 35 and 38 SNR.

When I had my FIOS installation seven years ago, they put a 1Ghz, 8-way splitter on the ONT output because the signal was so hot. I used that splitter until recently when I replaced it with an 8-way 1.2Ghz splitter.


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## Time_Lord (Jun 4, 2012)

I'm on FiOS and my signal strength is 100% with a SNR bouncing between 40 and 41.

First the SNR ratio, higher is better, just simply means that there is less noise (garbage) in the signal. I'm going to guess that the TiVo will work with a SNR of >30 without much if any issues, once you start getting to 30 or below you will probably start seeing pixalation issues. Things that can cause a lower SNR ratio, (if cable TV) poor drop from the outside, bad coax cable, bad coax termination, unconnected coax cable or unterminated (unused ports) on a splitter which will act like an antenna.

The signal strength, I'm not convinced that a high signal strength is a bad thing provided you are starting with a clean signal to begin with. I guess its possible you can over modulate the signal but at this point I'm having zero picture quality issues so I'm leaving well enough alone.

Going back to CoAX for moment, I can't tell you how many times a friend asks me to look at their TV because they have a lousy picture only to find the CoAX wire bent at some extreme angle where it goes into the connector, (believe it or not there is a minimum bend radius of 2.75 inches) and the braid is pulling out of the connector, or some heavy furniture is crushing the cable (yes deforming the cable causes loss).

My recommendation would be to use RG-6 CoAX, either /U (double shield) or /UQ (Quad shield) the Quad shield is probably overkill for the runs in a typical home. If you have RG-59/anything you are looking for problems as the wire is too thin and has a poor shield to carry the signals required for digital TV, it'll work for a short distance but even a medium size house maybe an issue.

BTW, my house I wired a home run of RG-6/U for each TV to the basement to a single splitter in the basement.

-TL


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## CrispyCritter (Feb 28, 2001)

As I've said previously (I thought to you), the TiVo SNR figure does not appear to be a true SNR figure; it measures something a bit different It is very well substantiated by numerous reports here that reducing a very high TiVo SNR level via adding attenuation or splitters can help picture quality.


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## BigJimOutlaw (Mar 21, 2004)

The FiOS signal can be pretty hot. Tivo's sweet spot is said to be in the 36 SNR range. I have 40 SNR and haven't had too many issues, but mileage will vary.

An attenuator or even a spare splitter behind the Tivo might help.


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## nooneuknow (Feb 5, 2011)

Time_Lord said:


> ...


TiVo's reading is NOT a TRUE SNR.

If it was, the highest you could get it, the better.

With TiVo, >36 can start causing A/V glitches, >38 can really make things messed-up, and >40 can damage the tuners, if the signal is reading 100% strength.

I find I generally have to drop my signal strength into the 80-90 range, in order to keep my (TiVo proprietary) SNR in the 33-37 range. That's (roughly) my "sweet-spot", YMMV.

I usually just advise against letting a signal be pegged at 100 strength, with a SNR >36, and as long as the strength isn't pegged at 100, higher SNR readings are less likely to damage anything (or shorten the life of the tuners). TiVo does have a protection mechanism, but it causes A/V glitches and A/V degrading, and isn't meant as a long-term solution.

TiVo's warranty does NOT cover damage to tuners, caused by excessive, or "hot", signals. While some who have fried their tuners did get warranty replacement, others did not.

*Please (everybody), don't go preaching things about the SNR on a TiVo, that doesn't apply to TiVo's secret (and idiotic) way they calculate it.
*
Good luck ever telling a cableco rep or tech that your "SNR is too high"...

I've heard rumors that the Roamio is better at not burning-out, but is still not completely immune to it.

Just because a TiVo seems to be "working just fine", doesn't mean it will continue on doing so, if it's having to deal with a "hot" signal...


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## aaronwt (Jan 31, 2002)

I certainly hope I don't have any issues. But if I do at least I got a four year warranty from BestBuy for my Roamio Pro. I shouldn't need to worry about my Roamio Basic with OTA since it's nowhere near as strong as my cable signal. Although I do have the Tivo 3 year warranty on it.


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## nooneuknow (Feb 5, 2011)

aaronwt said:


> I certainly hope I don't have any issues. But if I do at least I got a four year warranty from BestBuy for my Roamio Pro. I shouldn't need to worry about my Roamio Basic with OTA since it's nowhere near as strong as my cable signal. Although I do have the Tivo 3 year warranty on it.


Full disclosure: I've never heard of a 3rd-party warranty provider (outside of TiVo), denying warranty service for this. They don't have access to your logs, or any record of the calls you may have made to TiVo that may have brought the signal & SNR readings to TiVo's attention.

I'm not speaking of just some one-off claim, or that long-running (gossip) claim like that the only people denied warranty over a drive upgrade, told TiVo they upgraded their drive, etc.

I used to be able to keep my readings in the range that TiVo specifies on their website, before Cox went full 1GHz RF network here. Now, I sometimes have to let some channels drop too low, or just let some run too hot (sometimes both). I can only hope that as long as I'm making the effort, and not just letting most, or all, channels run hot, that I'm doing enough.

They key in the TiVo-calculated SNR, is that it's not truly "too high", so long as the signal strength isn't pegged at "100" (which is simply the highest it can read). What does that also non-industry standard way of measuring signal strength equate to in the industry standard (dBmV)? My tests point to it (100) meaning anything from ~0.0 dBmV (a perfect level) to *anything* in the positive (+) range (even double the acceptable level, and beyond). TiVo's signal strength at any level less than 100 represents any negative (-) dBmV range, which can drop pretty low, before it truly starts degrading things.

There can be scenarios where some have a ridiculously hot signal, and every channel reads 100 strength, and is accompanied by a high SNR (TiVo's version of SNR). These would be the ones in high danger of tuner-burnout. The built-in "protection" is some form of auto-attenuation, and has a limit to how much it can protect if always in-use, and just like any attenuator, it can only attenuate to a point. When somebody notices A/V glitches, often followed by what seems to be a loss of signal quality, that's sometimes the protection kicking in. It can either cycle in and out, or in extreme cases, always be in use. Sometimes the RS counts are a reflection of this mechanism cycling.

I think that's enough schooling for the moment. I have to get caught up on other things, for now.


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## kbmb (Jun 22, 2004)

nooneuknow said:


> I used to be able to keep my readings in the range that TiVo specifies on their website, before Cox went full 1GHz RF network here. Now, I sometimes have to let some channels drop too low, or just let some run too hot (sometimes both). I can only hope that as long as I'm making the effort, and not just letting most, or all, channels run hot, that I'm doing enough.


Making the effort? I didn't read anywhere on the Tivo box or in the manual that said I need to make a conscious effort to keep my cable signal within some "Tivo spec". 

If I don't have any issues, meaning I don't see picture dropping, pixelation, loss of signal.....why should I have to pay any attention to the Diagnostics screen?

Last I checked Tivo didn't popup a warning message saying my signal was too hot....or maybe that's what those Bounty ads are? ;-) If they don't warn me, how could it be my fault if someday a tuner fails? Just curious.

I had a TivoHD for 8 years and that had a 100% signal and 42-44dB SNR the entire time....never had an issue. Now with my Roamio Plus and Basic.....the Basic upstairs is 92-97% with ~35dB SNR, but the Plus is constantly 100% in the 40dB SNR range. (knock on wood) haven't had any picture issues. Is this "tuner too hot" a Premiere and above thing?

I too have seen where signals on some channels can drop and quite frankly I think I'd rather keep things on the high side with a perfect picture than run the risk of signal loss or major pixelation.

-Kevin


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## nooneuknow (Feb 5, 2011)

kbmb said:


> ...


To each their own, YMMV, and keep knocking on wood...

If you were to call TiVo, for some hypothetical issue, and they saw a constant "100% signal and 42-44dB SNR", it's not even hypothetical that they'd tell you it was too high. I'd bet a large sum of money on this. You can tell me you experienced otherwise (with TiVo CS), but I won't believe you.

I'm not saying TiVo CS is always (or even remotely) right. But, there's no shortage of threads and posts that back up what I said, as opposed to what you say.

I'll stick with what I said, and will (as a good-faith gesture), wish you continued luck, with your approach, on the matter.

I never said *everybody* with a excessively "hot" signal will kill their tuners, only that it can happen, has happened, and is not covered by TiVo's own warranty, if they have proof that it was the cause of a tuner failure. I was also careful to state that TiVo has replaced units damaged by such conditions, making it a YMMV (and matter of luck) situation.

I'll state that if you have channels that operate low, along with ones that are high, it's possible that your TiVo might never be on a hot channel long enough to damage the tuner. That's what I hope for in my situation. Once Cox went 1GHz, it became impossible for me to attenuate the all the "hot" channels to within TiVo's specs, without dropping others below TiVo's specs. More importantly, it was extremely hard for me to not induce low-signal issues on a great number of channels, by trying to bring down a few hot ones.

I guess that the support page proving the acceptable ranges was made because TiVo had nothing better to do? No, it's part of any TiVo's true manual, and would be considered operational requirements.

TiVo doesn't provide manuals with Roamios, and the manuals for the older models were basically "TiVos For Dummies", devoid of technical material, which incrementally became obsolete with each new software rollout.

I'd rather have just ignored your post, but opted to make sure others that see it get to see a counter-post, and be as fully-informed as possible, before deciding what to do, if they do bother to check their signal levels.

Even the lowly MSOs don't just plug in a STB or DVR without checking the readings, and adjusting them to within their own "acceptable" ranges. Since TiVo is also a retail product, in addition to being used by some MSOs, it becomes the retail buyer's responsibility to know the signal is within acceptable ranges.

Unlike you, I choose to err on the side of caution, and prefer my signals a bit low, in order to keep the high ones from being way too high. I comprehensively check my whole home at least once per season of each year, due to seasonal signal fluctuations, and change my splitter/attenuators accordingly, if need be.

I doubt you are on a 1GHz RF cable network, or you'd know that all this extra work I do, to monitor and adjust my signals, is forced upon me by the cable network I have to use, if I wish to use TiVo.


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## kbmb (Jun 22, 2004)

nooneuknow said:


> ......


First off let me say.....I appreciate your posts, and don't think I was knocking on you. I was more thinking it's absurd for Tivo to deny anything to a user based on having them check something when a box is working perfectly fine. Most people I know buy it, plug it in and if it's works....then do about their days.

Of course......this afternoon my Plus restarted for some reason and was stuck on the "Starting Up" screen. Had to pull the plug and restart.

I guess that's the Tivo God's telling to me not to talk bad about them!!

-Kevin


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## nooneuknow (Feb 5, 2011)

kbmb said:


> First off let me say.....I appreciate your posts, and don't think I was knocking on you. I was more thinking it's absurd for Tivo to deny anything to a user based on having them check something when a box is working perfectly fine. Most people I know buy it, plug it in and if it's works....then do about their days.
> 
> Of course......this afternoon my Plus restarted for some reason and was stuck on the "Starting Up" screen. Had to pull the plug and restart.
> 
> ...


OK. I guess I misread the "spirit" of what you posted. I'm kind of used to, and expect, some pushback around here. Sorry if I offended you.

I wouldn't even recommend TiVo to many people, due to that expectation of just plugging it in and working (like you said). I often regret being the person who "recommended TiVo" to those I did. I wind up getting more verbal abuse about TiVo, than whatever computer or software I might have recommended to that same person, or persons. Some people are better-off with an MSO-provided and installed box, since signal-drift, and out-of-range issues, are the MSO's problem to adjust, not the end-user...


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## mpnret (Dec 4, 2012)

nooneuknow said:


> If you were to call TiVo, for some hypothetical issue, and they saw a constant "100% signal and 42-44dB SNR", it's not even hypothetical that they'd tell you it was too high.


Exactly what happened to me. I called for a totally unrelated issue and when they saw my signal and SNR they immediately assumed that was it and had me attenuate the signal down to their preferred levels. Turns out that I solved the issue that I called for on my own but the new lowered signals were now causing errors along with video quality issues. I went back to my original setup which is running hot and everything is good. My RS corrected and RS Uncorrected is even better when running hot. Thing is, is running "hot" really running "hot"? I doubt it.


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## Time_Lord (Jun 4, 2012)

I would be careful about taking the word TiVo's tech support as gospel. I'll go out on a limb here and say they are judged on how many cases per day/week/month they close.

I know I've called with obvious bugs, found others were having the same issue, you call and they know nothing about it and say you must be doing something wrong or if they don't know the answer they'll give you something that sounds reasonable, or push the problem as yours (we don't support the TiVo being connected to a switch). I'm guessing the story with to high of a signal strength came from some customer that decided he needed a signal amplifier which only served to boost the noise as well (you know, garbage in, garbage out), once the customer removed the amplifier his signal strength dropped to something below 100% and the TiVo started working reliably again. Thus this CSR spread the word that a high signal strength is a bad thing without understanding the whole scope of the problem.

Just like I say my wife causes gray hair, I didn't have gray hair before I met her and her father didn't have gray hair before she was born, what's the common link? my wife, ergo my wife causes gray hair. In other words the logic although badly incomplete fits it must be correct. 

-TL


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## CrispyCritter (Feb 28, 2001)

Time_Lord said:


> I'm guessing the story with to high of a signal strength came from some customer that decided he needed a signal amplifier which only served to boost the noise as well (you know, garbage in, garbage out), once the customer removed the amplifier his signal strength dropped to something below 100% and the TiVo started working reliably again. Thus this CSR spread the word that a high signal strength is a bad thing without understanding the whole scope of the problem.


Sorry, you are just totally wrong here. There have been a large number of people just in these forums (well over a hundred at least) who have reported high signal strength and a bad picture, inserted attenuators or splitters, and have solved their picture problems. This has been true for every model of TiVo from the S3 on (well, probably not the Mini except indirectly). TiVo engineers talked about it here in the early HD days.


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## nooneuknow (Feb 5, 2011)

mpnret said:


> Exactly what happened to me. I called for a totally unrelated issue and when they saw my signal and SNR they immediately assumed that was it and had me attenuate the signal down to their preferred levels. Turns out that I solved the issue that I called for on my own but the new lowered signals were now causing errors along with video quality issues. I went back to my original setup which is running hot and everything is good. My RS corrected and RS Uncorrected is even better when running hot. Thing is, is running "hot" really running "hot"? I doubt it.


"Hot" is a term for an excessively strong signal. On it's own, it has nothing to do with actual heat.

However, when the scope is broadened to include the tuner components, a "hot" signal increases the temperature of the components that have to process it. The amount of added heat is proportional to the strength of the signal.

An attenuator is a simple resistor, designed to lower the signal. They will generate a minute amount of heat, as all resistors create heat.

I think I've already gone out of my way to state YMMV, and there are many variables involved.

Also, TiVo CS tends to push you to over-attenuate, in general. So, I can't rightly argue that you are in the wrong, or dispute your experience.

I try not to use attenuators, due to the simple resistor method for attenuation. Attenuators caused me problems, as well, so they are a last-resort.

Another way to attenuate a signal down is by using splitters. You can either change the number outputs to a higher number, which will result in a lower signal, and terminate the unused ports, or daisy-chain splitters to do the same thing. It's just always important to not leave unused ports "open" (without a terminator), as it allows noise into the signal via ingress, and can leak out signal, via egress.

Due to higher frequency signals being attenuated at a different level than lower frequency ones, the higher frequency cable network you are on, the more of a PITA it is, to try and wrangle all frequencies, with a simple resistor-based attenuator.

For me to say much more, I'd just be repeating myself.


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## nooneuknow (Feb 5, 2011)

Time_Lord said:


> I would be careful about taking the word TiVo's tech support as gospel. I'll go out on a limb here and say they are judged on how many cases per day/week/month they close.


Yet, you seem to be upset that I called you out on your own gospel, and are now using TiVo's often clueless CS center to back yourself up...

Another post where I'm best-off to just stick with what I have already said, and not repeat myself.

Those wanting to know more, can find many threads, with many posts, that cover the subject thoroughly, in-depth, with many POVs and many experiences, accumulated over many years. I advocate taking the time to review the official TiVo support page on the subject, and taking the time to read the vast amount of data-points available in threads that predate this one. Everybody should make an informed, educated, decision. Everybody should not choose one of my views, or your views, without doing their own due-diligence on the subject.

Example of an unrelated YMMV situation, that can go wrong:
I found that I can recharge my Li-ion batteries faster if I use a charger that operates at a higher voltage and current than the correct one. None have blown-up, or caught fire, yet. That doesn't make it the right charger to use, nor do my results mean that somebody else doing the same thing won't cause anything from a life-shortened battery, to a catastrophic explosion and getting their house burned down. I know the risks, and made the choice to allow that very danger to be possible. So, I only do so in a pinch, and take other precautions to avoid the danger, which will always be there.


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## mpnret (Dec 4, 2012)

nooneuknow said:


> "Hot" is a term for an excessively strong signal. On it's own, it has nothing to do with actual heat.


I never meant to indicate that hot had anything to do with actual heat. What I did mean is we have no idea what 100% indicates in the TiVo world. I've attenuated with both attenuators and splitters and find that for my particular situation I'm better off running hot.


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## kbmb (Jun 22, 2004)

mpnret said:


> I never meant to indicate that hot had anything to do with actual heat. What I did mean is we have no idea what 100% indicates in the TiVo world. I've attenuated with both attenuators and splitters and find that for my particular situation I'm better off running hot.


I'm similar to you......tend to find that running 100% with 41-43dB gives me a perfect picture and no corrections. Ran my TivoHD on the same line that way for 8 years.

The problem with Tivo's reading is you have no idea if what you are running is the equivalent to 103% or 123%. Like you said....is hot really not "hot". Seems to me a perfect signal would be right on 100%.

This notion that Tivo always wants you to attenuate to get down to something less than 100% seems absurd to me. Doesn't mean I'm right.....just sounds absurd. Wish my parents were ok with me attenuating my grades years ago ;-)

If they would just also show an actual signal level, then I think a lot of this would be solved.

However, if you are a user and showing 100% and are having the cutouts, pixelation, signal loss.....then yeah, I'm guessing your signal is TOO hot. But again, Tivo has to guess just as much as we do since they don't show an actual number!

-Kevin


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## kbmb (Jun 22, 2004)

nooneuknow said:


> I try not to use attenuators, due to the simple resistor method for attenuation. Attenuators caused me problems, as well, so they are a last-resort.
> 
> Another way to attenuate a signal down is by using splitters. You can either change the number outputs to a higher number, which will result in a lower signal, and terminate the unused ports, or daisy-chain splitters to do the same thing. It's just always important to not leave unused ports "open" (without a terminator), as it allows noise into the signal via ingress, and can leak out signal, via egress.
> 
> Due to higher frequency signals being attenuated at a different level than lower frequency ones, the higher frequency cable network you are on, the more of a PITA it is, to try and wrangle all frequencies, with a simple resistor-based attenuator.


That's interesting and the first I've heard that. So you think it's better to split the signal (terminating unused ports) than simply applying a traditional attenuator?

-Kevin


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## leepoffaith (Apr 21, 2014)

Thank you for all the feedback! Everyone on this Tivo forum is so helpful. I've decided that, for the time being, I'm going to keep it as is. 98% of my channels are crystal clear (better then the fios box was in my opinion). I was able to watch a Cinamax movie last night without an issue as well. I had this problem once before about 2-3 years ago with the standard FiOS boxes and they had to end up replacing the ONT box. I have the ONT on the outside of my home and I believe the Florida sun really takes it's toll on it.

I am going to be purchasing a coaxial compression tool, coaxial stripper/cutter and a bunch of compression fittings so I can replace all my connections in my OnQ box (where all my cable lines come in to). Right now they are the old school small connection where you just crimp the end. I will also be cutting an appropriate length cord to use with the Roamio because I realized that I am using too long of a cord and it is bending in a weird way. 

If after getting the cords all set I still have the issue I will look into purchasing a 6 db attenuator.


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## nooneuknow (Feb 5, 2011)

From another thread: http://www.tivocommunity.com/tivo-vb/showthread.php?p=10097616#post10097616



ToddK1970 said:


> Well I am one of the owners of a Roamio Plus that was affected. I had the Roamio for 1 month and 8 days. When I called support they told me my SNR was too high since it was at 43db. They said to fix that and see what happens. Got a hold of FIOS and scheduled them the next day to come out. In the mean time the latency between channel changes went from about 10 seconds to 40. I then started getting the V52 signal and lost all video. Tivo rep still insisted ist was SNR and Fios problem.
> 
> So I disconnected the Coax and it would not even play any of my recorded shows. They finally said oh it may be a bad box. Then they said the SNR is probably what killed it. So I paid for a new box and they shipped it me. Once I return my old on they will credit me. So I have had the new one since last Friday. I will see how it goes. I had really loved it until last week.


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## nooneuknow (Feb 5, 2011)

kbmb said:


> That's interesting and the first I've heard that. So you think it's better to split the signal (terminating unused ports) than simply applying a traditional attenuator?
> 
> -Kevin


Based on my own experience: Yes, absolutely.

It's also worth noting that the local Cox techs are prohibited from using attenuators. All attenuation must be done using splitters, and simply terminating any unused (extra) ports. Any attenuators found while out on a truck-roll, must be removed.

I had no issues with attenuators before Cox went to 1GHz, and then the spectrum became too wide mange equally/properly with them. While the attenuators they had been using were 1GHz rated, the problems with the difference in high and low frequencies, and how much the same attenuators would change the signal, pretty much required using splitters.

I don't know if you've ever opened up a modern MSO-grade splitter, but I have, and there's a lot more to a splitter than most probably think. They really should be called "distribution and isolation devices", as "splitting" paints a crude picture, compared to what's really going on. I've seen many post things about how they think splitters work, and many of them are very wrong.

What's fun is to peel the metal back off a cheap splitter like "Gemeni" brand, and then do the same with one that came from your cable company. It's hard to believe those junk ones ever worked for anything.

Splitters will always do a better job (even if only by a marginal amount, in some cases) of keeping the attenuation more equal across all frequencies. It's more work to do, that way. But, IMHO, well worth the effort. I doubt Cox would prohibit using basic attenuators, unless there was a need to. Attenuators are cheap and easy to quickly install. Between parts and labor costs, I'm sure the splitter-only rules have to be worth it, or they simply wouldn't go that route.


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## ustavio (Oct 19, 2013)

I've had various experiences with and without attenuators and splitters. I have a TiVoHD and a Roamio Pro. Until recently, I had two Verizon Fios Set Top Boxes and ran the HD and Pro side by side with the STBs via splitter.

With the Pro, I found that when my SNR (at 100%) was 40-42db, the Fios STB was giving me a reading of 35-37db. The TiVoHD gave me an almost compatible SNR at 37-38db. Both TiVos and STBs were using high quality Regal/Antronix splitters with 3.5db loss on each split. Without splitters, the Pro gives 40-44db and the HD still gives 37-38db. With both the Pro and HD I experienced zero RS uncorrected and uncorrected before and after splitter use. The only way I've been able to get Signal Strength below 100% is to use multiple splitters and/or attenuators. Using 6-12db Holland, I can get into TiVo's preferred zone and drop SNR on the Pro to under 40db and the HD to 30ish, depending. Individual channels can range the gamut of higher and lower. However, I find a RS corrected and uncorrected errors occur frequently and more importantly, I get audio and/or video pixilation issues and other glitches I did not have before.

I ditched the Fios STBs to embrace the pure TiVo experience (okay, really to save money) so I no longer have the ability to compare SNR values but with all the experimentation (splitters, attenuators, splitters with attenuators, splitters daisy chained with splitters, splitters daisy chained with splitters plus attenuators) and with all the resulting various Signal Strength and SNR values on both the Pro and HD, I have found that using nothing gives me the best picture and audio quality.With unadulterated out of the wall Coax, I get on the Pro, 40-43db pegged at 100% (depending on channel) and on the HD I get 37-38db pegged at 100%. I also get zero RS corrected and uncorrected. On the HD i get very occasional RS changes when I leave one channel tuned in all the time (my wife likes HGT V), but they also seem to occur when Fios does a channel lineup change, or there is a Service Connection or a Fios line hiccup. The only reason I know this occurs is because the OCD part of me checks every now and again. More importantly, if the RS corrected or uncorrected has changed, it is not "changing" in front of me. Almost always, these will go away with a VCM connection. Rarely, if it is on a channel that has been locked for weeks on end, just changing the channel back and forth dispatches the errors. Regardless, the picture/audio quality remains solid.

I agree that splitters do a better job than attenuators at bringing values into TiVos preferred range. But the preferred range (Signal Strength >75 <100) (SNR >32 <36) is difficult if not impossible to achieve on all channels, all the time whether using splitter(s) or attenuators(s) or a combination of the two. While I might get it on channel A, on channel B I would get a SS of 53 and SNR of 24. Pixilation and various glitches were quite plentiful. Especially when changing between channels with "approved" values and those that fell outside them. Recorded shows were hit and miss, many were just unwatchable.

If one throws into this mix, an issue on Fios' end or a specific channel having a seizure or ESPN experiencing live transmission problems (of which they sometimes neglect to inform the viewer until after said viewer has had a seizure), it is sometimes near impossible to determine if audio/video quality issues are internal or external or both.

I've been fiddling around with this stuff for years now. It was even more of a nightmare with TWC their tuning adapter and the platform issues they inherited from Adelphia.

So far I haven't burned out any tuners (knock on wood) but I have fried my brain over signal strength/SNR values. As of today, my cranky old TiVoHD and spiffy Roamio Pro seem to function best with no splitters or attenuators, a signal strength pegged at 100% (on all channels) and an SNR that runs 40-43db on the Pro and 37-38db on the HD. I can, however, fully understand and appreciate, given the multiple variables involved, why folks have different experiences with different Cable/ISP systems and set ups.


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## kbmb (Jun 22, 2004)

ustavio said:


> I've had various experiences with and without attenuators and splitters. I have a TiVoHD and a Roamio Pro. Until recently, I had two Verizon Fios Set Top Boxes and ran the HD and Pro side by side with the STBs via splitter.
> 
> With the Pro, I found that when my SNR (at 100%) was 40-42db, the Fios STB was giving me a reading of 35-37db. The TiVoHD gave me an almost compatible SNR at 37-38db. Both TiVos and STBs were using high quality Regal/Antronix splitters with 3.5db loss on each split. Without splitters, the Pro gives 40-44db and the HD still gives 37-38db. With both the Pro and HD I experienced zero RS uncorrected and uncorrected before and after splitter use. The only way I've been able to get Signal Strength below 100% is to use multiple splitters and/or attenuators. Using 6-12db Holland, I can get into TiVo's preferred zone and drop SNR on the Pro to under 40db and the HD to 30ish, depending. Individual channels can range the gamut of higher and lower. However, I find a RS corrected and uncorrected errors occur frequently and more importantly, I get audio and/or video pixilation issues and other glitches I did not have before.
> 
> ...


I have had a very similar experience to yours. When I first got my Plus, noticed the 100% signal and 41-43dB. I brought my Comcast DVR down and plugged it into that same connection and it displayed the SNR in the 37-38dB.

I noticed my Basic is more in the 37dB range, but that's on a longer cable run. I guess one of these days I should bring the basic down and see the difference between that and the Plus on the same run.

-Kevin


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## kbmb (Jun 22, 2004)

So I thought I'd actually do this experiment this morning because I was curious.

My setup is Comcast. I have a single cable run from the pole to the basement of our house. Inside the house it's split with a 3-way splitter:

-7dB: to the cable modem on the 1st floor (about a 10' run)
-7dB: to the Roamio Plus on the 1st floor (about a 25' run)
-3.5dB: to the Roamio Basic on the 2nd floor (about a 60' run)

With this setup:

The Roamio Plus is consistently at 100% signal and 41-43dB SNR. Have had no issue with this.

The Roamio Basic has a signal of 92-95% and ~37dB SNR

So what I decided to do this morning was swap them to see what would happen with the signal levels. Well, I was half expecting that the levels would swap and stay at the location.....but they didn't. The levels followed the Tivo, so moving the Plus upstairs on the longer run, it had the exact same signal levels as downstairs, and the Basic on the shorter run downstairs had the same as when it was upstairs.

No doubt the Plus/Pro have to boost the signal to get the 6 streams....but it's looking like that signal is really boosted compared to the Basic.

-Kevin


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## nooneuknow (Feb 5, 2011)

kbmb said:


> So I thought I'd actually do this experiment this morning because I was curious.
> 
> My setup is Comcast. I have a single cable run from the pole to the basement of our house. Inside the house it's split with a 3-way splitter:
> 
> ...


I keep forgetting the 6-tuner model (Plus/Pro) discussions tend to lead down this path...

Now I seem to recall some folks very unhappy with the amplification being always-on, and TiVo blaming the source signal for damaging things, etc.

Good move swapping things around. That made sense.

I also tend to use my Tuner Adapter readings to see a true, non-TiVo, reading, and you should see a lower SNR value on the TA (being a true SNR, not TiVo calculated). This is only valid if using a two-way split, with equal-length cables, to the TA and TiVo, without any attenuators in-line, after that split.

I'm also now recalling some TiVo advice that involves pulling the coax, then checking the reading to make sure they go to zero/null values. TiVo considers any other result to be a TiVo fault condition.

I kept talking about the other threads that predate this one. Yet, I didn't go back and pour over them again, where I'd have spotted some reminders on the Plus/Pro differences.


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## kbmb (Jun 22, 2004)

nooneuknow said:


> I keep forgetting the 6-tuner model (Plus/Pro) discussions tend to lead down this path...
> 
> Now I seem to recall some folks very unhappy with the amplification being always-on, and TiVo blaming the source signal for damaging things, etc.
> 
> ...


Don't have a tuning adapter, so can't use that as a measurement....wish I had one of those tools the cables guys have. Back in my TivoHD days, we were having issues that we thought were signal related.....the Comcast guy came out and saw that all signal levels were fine (turned out to be some issue on Comcast's side). And like I said before....before we got the Basic, we had the Comcast DVR and I hooked that up to the same line as the Plus and it read lower SNR numbers.



nooneuknow said:


> I'm also now recalling some TiVo advice that involves pulling the coax, then checking the reading to make sure they go to zero/null values. TiVo considers any other result to be a TiVo fault condition.


Just because I love testing these things, I went and pulled the coax on both my Tivos:

Roamio Plus coax plugged in:
Signal: 100%
SNR: ~41dB
OOB SNR: ~35dB

Roamio Plus coax UNplugged:
Signal: -
SNR: ~17db (although saw one jump to 29dB)
OOB SNR: ~3-4dB

------

Roamio Basic coax plugged in:
Signal: 92-95%
SNR: ~37dB
OOB SNR: ~400dB (not sure why the Basic shows this number)

Roamio Basic coax UNplugged:
Signal: -
SNR: ~9-15db
OOB SNR: ~44-47dB

-Kevin


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## nooneuknow (Feb 5, 2011)

kbmb said:


> Just because I love testing these things, I went and pulled the coax on both my Tivos:
> 
> Roamio Plus coax plugged in:
> Signal: 100%
> ...


I'm going to have to defer analysis of these results to somebody who remembers what thread this was covered in.

Either I don't know the "secret" to searching TCF, or I just suck at it...

The truth is out there. ...somewhere...

Next time I have the opportunity to check mine, I will. I'll probably stick a terminator on the input to eliminate any stray RF that might get in (although, this was not a specified prerequisite in the thread I'm recalling).


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## kbmb (Jun 22, 2004)

nooneuknow said:


> I'm going to have to defer analysis of these results to somebody who remembers what thread this was covered in.
> 
> Either I don't know the "secret" to searching TCF, or I just suck at it...
> 
> ...


Maybe this is the thread you were thinking of:
http://www.tivocommunity.com/tivo-vb/showthread.php?t=514853

Based on 1 person saying Tivo said it was defective and they got it RMA'd....although I'm not sure I would trust much of what Tivo support says. These days they generally tend to be mostly clueless.

I notice back then I also pulled the coax on my Tivos and reported the numbers.....although see numbers are a little off because I had an old setup.

Would be curious to see others if they have a SNR when the cable is pulled. Again....I'm not having issues so not sure what the difference is.

-Kevin


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## triftraf (Jan 26, 2006)

I was one of the people that had their Roamio Pro's RMA'd. The new Roamio actually showed even higher SNR and ended up requiring MORE attenuation/splitters to get the signal strength and SNR low enough. It seemed more sensitive to the problem than the first one. The first one ran beautifully for a week before issues started showing up - whereas the new one did all sorts of weird stuff (lagging, losing signal, rebooting and not starting up, etc) without attenuating...

Both units (the RMA'd one and the new one) show SNR when the cable is disconnected... And thus I don't believe the first unit needed to be RMA'd...


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## nooneuknow (Feb 5, 2011)

kbmb said:


> Maybe this is the thread you were thinking of:
> http://www.tivocommunity.com/tivo-vb/showthread.php?t=514853
> 
> Based on 1 person saying Tivo said it was defective and they got it RMA'd....although I'm not sure I would trust much of what Tivo support says. These days they generally tend to be mostly clueless.
> ...


That's not the one I was thinking of. I also wouldn't consider a one-off report from one person to be reliable enough to base an opinion on that I'd repeat.

Until I spot what else I've seen again, or somebody else finds it, I'm kind of dead-in-the-water on any meaning of the "disconnected cable test".

I swear there was a thread where the test resulted in a few people getting RMAs. I'd be hesitant to RMA one of my own, unless I was certain it needed to be replaced. I'm not feeling to confident that this "test" proves much.

I'll still report back when I get a chance to try it on my 3 base Roamios. I'll be doing:

1. Base reading, for each tuner.
2. Pulled coax cable readings.
3. Readings with terminator on input.
4. Readings after a reboot.

I'd add 5. Readings w/o cablecard inserted. But, they are hard to get to on base models.


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