Home Distribution Port

John Corn

The Coach / Supporter
Original poster
Supporting Founder
Sep 6, 2003
1,237
19
North Canton, Ohio.
I distribute a signal to a 2nd TV through my home distribution port, as of 4 days ago ive been waking up to no picture, im assuming after it goes into sleep mode or the 3am reboot it causing me to lose my picture on tv2 only. After waking it up by changing channels I get my sound back but still no picture........any ideas?
 
A hard or soft reset does work, I'm just wondering why?
I called Dish but they wouldn't do anything until I called back when It happend again.
 
Your 2nd TV could be off frequency, especially for older analog CRT TV's and we are talking exclusively RF signals. In other words, if your TV loses the signal--no video and audio--the AFT (Automatic Fine Tuning--built in and always working in the background on TV's since the 1980's, no manual fine tuning ring around the round channel selector on 1970's and before models) keeps trying to tune to lock onto a frequency with a carrier. Essentially, it drifts into the neighboring channel as there is no signal on the channel it is supposed to be tuned to to keep locked on the correct frequency. Then when carrier returns to the channel your 2nd TV is supposed to tuned to, it is still locked onto the neighboring channel for video, but it is common for audio to lock properly while video is lost. This is really a rather common thing.

The solution is to re-tune to the channel original channel the 2nd TV is supposed to receive the Dish TV2 picture. This usually sets things right, but the AFT has now been pretty much set off frequency, which means that this will happen all over again once the TV loses video via RF. If you keep allowing this to occur, that is not set the TV to shut off before it loses video, the TV can become "permanently" off frequency (it will be stuck on the neighboring frequency and it won't tune back to the original RF no matter what you do), and you will have to have TV technician put your TV back on frequency.

This happens almost every night with my mom's old CRT in the next room being fed RF from Home Distribution, but, fortunately, the loss of video doesn't last that long and the AFT will lock on to the correct frequency or when it doesn't, we can re-tune to the original frequency with ease.

This is a problem ONLY for RF, not for the inputs of a TV. The inputs can have no signal on them and not be "ruined" by a lack of video and audio If you drift off frequency in the short 4 minutes that there is no video, then your AFT is already off frequency to a fair degree. In order for this to be a problem, the TV has to be tuned to a channel with no carrier for some hours OR--the big OR, dealing with loss of video--even in short periods of lost video--repeatedly over a LONG TIME. Loss of video for just a few minutes every day for 6 months to a year or more (depending on the TV's particular AFT) will add up to a problem as if you left on a channel with no carrier for many hours. Never, leave ANY TV on an analog RF channel, including an OTA "digital" frequency, which is still RF analog technology (as opposed to a Dish sat channel with no signal or black, for our purposes, that would be considered a digital channel) with no carrier whenever possible and one can avoid a tuner becoming off frequency.

Let us know what the problem ends up being.
 
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Thanx for the reply, I'm still not sure what is causing this, again today it did it again after waking up this morning.
My 2nd TV is a 32" Dynex LCD (2yrs old) , its been fine till approx 6 days ago.
 
John Corn said:
Thanx for the reply, I'm still not sure what is causing this, again today it did it again after waking up this morning.
My 2nd TV is a 32" Dynex LCD (2yrs old) , its been fine till approx 6 days ago.

What channel is ur tv2 on? If it is on something other than what modulator setup is on I would suggest making the channels match. Because the different frequencies will sometimes cancel eachother out.
 
And when this happens, do you re-tune or re-enter the RF channel on your TV? Does this bring things back the way they should be? What do you have to do to have video and audio return to the 2nd TV? Try another analog channel, as suggested by another poster. That could solve the problem. OR if it is an off frequency TV problem, solve it for a while, anyway.
 
I think the suggestion from the poster is saying that you don't have the channel being sent out by the Home Distribution the same as the channel your use on TV2 to watch the box.

ALSO, analog Cable channels (65-94 and 100-125) are only 2MHz below the OTA UHF broadcast channels, so if there are OTA broadcast channels in the line with or somehow leaking into the line/cable you use for your TV channel, then you will have reception problems on the 2nd TV as the equivalent broadcast UHF will interfere with the Cable analog TV channel.

For example, analog channel 73 operates within the allotted bandwidth of UHF channels (2MHz below or above) 21 and 22, while cable channel 75 operates within the bandwidth of UHF channels 23 and 24 and if carrier is on more than one of those 3 channels withing that bandwidth, there will be interference. In fact, although one of the channels you use to receive TV2 on your second TV is Cable Channel 73, you can probably tune you 2nd TV to UHF channel 23 and see the picture there because you TV's AFT is locking onto the carrier at 2MHz below the cable channel 73, it is that close to each other.

Now, the logical thought is, "My cable TV for many years had no interference problems when tuning to channels a mere 2MHz apart such as OTA channel 4 and cable channel 66." That's because cable TV systems use expensive notch filters to isolate the channels so they don't interfere with each other.

It could be a problem with the Home Distribution, meaning the box itself, but you could still have a TV off frequency(especially since you say this problem only started recently and manifests itself upon "waking-up" your 2nd TV), so try to eliminate that, as well. If you still have this problem after having successfully set to new channels for TV2, then I would suspect an off frequency TV. It sure sounds like an off frequency TV behavior to me. I have seen this a number of times over the years.
 
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