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Discussion Starter · #1 · (Edited)
Within the last several months (which seems to coincide with my cable company making the all digital switch), I’ve had odd issues with SDV channels. An example would be tuning an SDV channel, then watching a recorded program for approximately 2-3 minutes. After returning to live TV, the previously tuned SDV channel shows “There is a problem with the signal on this channel”. The really odd part is that when I re-tune the offending SDV channel, the channel frequency is different. Is it possible that for some reason the SDV server at the head end is changing frequencies more often than normal and TiVo isn’t aware and therefore trying to tune to a non existent channel frequency?

I have an open case with TiVo which has was escalated over a month ago and I’m just not sure how to proceed at this point, as it’s clear that this isn’t an equipment issue but either an issue with how SDV is being implemented by my cable company or a TiVo software issue/bug...

My cable company is Spectrum in Richmond, KY
 

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I've had Spectrum (formerly TWC) with SDV (i.e., requiring a Tuning Adapter [TA]) for ten years now in the Dayton OH area. They have never achieved totally flawless SDV performance during that period. At its best it works OK for a month or so then the TA must be power-cycled and the USB connector must be cycled, and sometimes the Tivo must be restarted too. (I'm assuming you have a TA connected -- absolutely necessary to get SDV channels and should be furnished free by Spectrum.)

The SDV system, even when operated correctly, is allowed to drop the frequency of a channel if it decides you aren't watching or recording that channel. This happens on my system but after something like a half hour, not just a few minutes. Also the message when this happens on my system is something like "this channel is temporarily unavailable, press select to re-tune" (approximate wording from memory). And if you press select and wait a few seconds and press select again it usually will retune the channel. The SDV system by the very nature of its operation can assign a different frequency to the channel when it is re-tuned. This SDV channel-dropping behavior became a lot more frequent after Spectrum took over my TWC system.

You may have problems with signal levels in the OOB (out-of-band) control signals that are dedicated to communication between the TA and the cable system. In TA diagnostics, Status Summary .... Next Page, what are the dBmv values of FDC and RDC? FDC should be between -5 and +5 and RDC should be between 30 and 50.

Good luck with Spectrum -- this forum is filled with TA-related Spectrum horror stories. One key tip is: request that support transfer you to the national CableCARD help desk (in Buffalo, NY). They actually have a clue about TiVo's, CableCARD's and TA's, while local support may not even know what those things are.
 

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Discussion Starter · #3 ·
I've had Spectrum (formerly TWC) with SDV (i.e., requiring a Tuning Adapter [TA]) for ten years now in the Dayton OH area. They have never achieved totally flawless SDV performance during that period. At its best it works OK for a month or so then the TA must be power-cycled and the USB connector must be cycled, and sometimes the Tivo must be restarted too. (I'm assuming you have a TA connected -- absolutely necessary to get SDV channels and should be furnished free by Spectrum.)

The SDV system, even when operated correctly, is allowed to drop the frequency of a channel if it decides you aren't watching or recording that channel. This happens on my system but after something like a half hour, not just a few minutes. Also the message when this happens on my system is something like "this channel is temporarily unavailable, press select to re-tune" (approximate wording from memory). And if you press select and wait a few seconds and press select again it usually will retune the channel. The SDV system by the very nature of its operation can assign a different frequency to the channel when it is re-tuned. This SDV channel-dropping behavior became a lot more frequent after Spectrum took over my TWC system.

You may have problems with signal levels in the OOB (out-of-band) control signals that are dedicated to communication between the TA and the cable system. In TA diagnostics, Status Summary .... Next Page, what are the dBmv values of FDC and RDC? FDC should be between -5 and +5 and RDC should be between 30 and 50.

Good luck with Spectrum -- this forum is filled with TA-related Spectrum horror stories. One key tip is: request that support transfer you to the national CableCARD help desk (in Buffalo, NY). They actually have a clue about TiVo's, CableCARD's and TA's, while local support may not even know what those things are.
Thanks for your suggestions and insights. That said, I wasn't able to find the specific TA diagnostics you spoke of. I went though each menu but didn't specifically see FDC and RDC levels. Perhaps they are referred to differently on my particular TA (Motorola)?
 

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Thanks for your suggestions and insights. That said, I wasn't able to find the specific TA diagnostics you spoke of. I went though each menu but didn't specifically see FDC and RDC levels. Perhaps they are referred to differently on my particular TA (Motorola)?
That's probably the case. Most Spectrum systems use Cisco TA's but some apparently use Motorola's. I can't help you with diagnostics on the Motorola but I'm sure another forum member can.

In any case, the issues you have are not acceptable and Spectrum is responsible for fixing them. The odds that this is a TiVo problem are miniscule.
 

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Discussion Starter · #5 ·
That's probably the case. Most Spectrum systems use Cisco TA's but some apparently use Motorola's. I can't help you with diagnostics on the Motorola but I'm sure another forum member can.

In any case, the issues you have are not acceptable and Spectrum is responsible for fixing them. The odds that this is a TiVo problem are miniscule.
Thanks so much for all of your help, I am truly grateful! I agree that this is most likely a spectrum issue. I just got off the phone with cable card support and set up a call with maintenance in the hopes that I can escalate this to the head end to take a closer look at it.
 

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I am having the same issue with Charter/Spectrum which I believe is related to the way that the Tivo Bolt uses the Tuning Adapter (Motorola MTR700) to enable Switched Digital Video (SDV) channels. It started a few months ago so Spectrum must have changed something in the way they control the SDV channels

The Tivo has four channels. I frequently watch two (or more) channels at the same time, switching between them during commercials.

The issue I have is that sometimes when I switch back to a channel that I have not viewed for a few minutes, I get the "This channel is temporarily unavailable." message. If I reselect the channel it comes right back, but the recording on that channel is lost.

After much research, I discovered (looking at the Tuning Adapter diagnostics screen) that if I am not actively watching the channel, the channel feed is deactivated by the SDV controller after about two minutes. However, if I am watching that channel on another receiver this does not happen. Also, once in a while I will get this message on a channel I am watching if it has been on for a while. This does not happen if I am recording the channel I am not watching.
While this is more of a Spectrum issue, I believe that it might be possible that Tivo could prevent this by changing the way it uses the Tuning Adapter.

I don't know the details, but apparently Tivo sends a signal to the SDV controller that it is either actively watching a channel, or that it is recording a channel. It does not seem to do this for the unviewed channels that are not being "fully recorded", even though it is saving the most recent 30 minutes on those channels.

Charter/Spectrum could (sort of) fix this by changing the SDV timeout to 30 minutes or more, but I would really like to be able to see the previous 30 minutes on all the Tivo channels even though I have not been recently "actively" watching them.

I think that Tivo should tell the SDV controller that it is "recording" or actively viewing all its channels so that the SDV controller does not deallocate them.
 

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Hard to say for sure whether either TiVo or Spectrum could fix this but AFAIK this behavior is allowable on an SDV system. Most systems wait longer than 2 minutes to drop an unwatched/nonrecording channel but it depends on how many SDV channels they’re squeezing into a limited bandwidth. I’m afraid you’re whistling into the wind on this one.
 

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Is there anything that I can do on my side to resolve this type of issue? I just recently noticed it happening on one of my TiVo boxes. This is happening on my 6-tuner Roamio that has an attached Motorola tuning adapter. I have found that when watching tv if I switch tuners and then go back to one that was on an SDV channel, I get the message that this channel is temporarily unavailable. I can press the select key and the channel immediately comes back. However, I have lost my buffer. The biggest issue is that it interrupts recordings on that channel. It records ok as long as I stay on that channel on live TV. Even if I go to the menu to switch to viewing another recording or even just bringing up some diagnostics, my recording stops. I am trying to tape a Christmas movie right now for my mom, but if I switch off of that tuner, my recording immediately stops.

I noticed in the diagnostics menu that any time a tuner was on one of the SDV channels the signal strength is at 100% and the SNR is at 40. My non-SDV channels have a signal strength in the 90’s and an SNR in the 30’s.
I tried adding a splitter going into the TA and it dropped the SDV channel signal strength to 97 and the SNR to 39. I had hopes that reducing those numbers would alleviate my issue but it did not. I hesitate to contact Spectrum since they are usually not that well-versed with how TiVos work with their system/equipment, and I don’t specifically know the root cause of the issue.

Does anyone know what could be causing my issue? I think I have a spare TA that I could try swapping out. Is this an issue with my Spectrum signal, Spectrum amplifier, Spectrum tuning adapter, my splitter setup, my TiVo box or something else? I can check other values in the diagnostics screens if necessary if someone could tell me what to check to help diagnose this issue. (I just have to wait until my current movie which is on an SDV channel finishes recording!)

Any help would be greatly appreciated!
 

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They are doing excavation and tree removal on the lot next to me. Could that possibly be messing with my cable to cause issues with my SDV channels as described in my previous post? I contacted Spectrum and they sent new signals to all of my equipment but that didn’t fix the problem.
 
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