# OTA flaking out -- could this be the 921?



## gerbildude (May 27, 2005)

I pick up the Sacramento area OTA stations, but I've been having some problems and I'm not sure if this could be 921 flakiness or not.

When we first installed an antenna everything was good, and we watched OTA stuff without incident for a few months. Then a little over a month ago our Fox station (040-01) went nuts. The normal signal strength is about 90, but it started dropping from 90 to 0 and then back up every few seconds or so, resulting in constant pixellation and sound breakups. I pestered our antenna installation dude, but he seemed confident it was a 921 problem rather than the antenna setup. After about a week the problem suddenly just cleared up, so I let it go.

However, for the past couple of weeks we've lost several of the PBS stations. PBS broadcasts on 4 stations (006-01 through 006-04), and although we were picking them all up just fine (with signal strength around 66-70), now we only seem to be able to get one (006-02). The other channels are still there and show the same signal strength, but we just get a black screen when we try to watch them.

I've checked AVS forum about both of these incidents no one seems to have been complaining about similar problems. I've also tried resetting the 921 (with soft boots) to no effect. At this point I'm not sure if I should be after the antenna installer about this issue or Dish with the 921. Does anyone else have experience with similar OTA goofiness and the 921?


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## boylehome (Jul 16, 2004)

gerbildude said:


> I pick up the Sacramento area OTA stations, but I've been having some problems and I'm not sure if this could be 921 flakiness or not.


Welcome aboard!
Farther North from you, some of our stations are not at full power yet. They occasionally get flaky as you describe. I have experienced what you describe with our sticks stations. I have callled the chief engineer at one station, ABC, and found that it was a problem at their end. Aside from possible antenna, cable, or receiver problems at our end (like a poor connection at the antenna that is affected by temperature change, moisture or movement) the stations may be having equipment probems or are working on power issues, and may even be testing equipment at repeater sites and adjusting signal power.

Also it sounds like you may experience multipath. Is there something newly erected near you with a reflective surface? The foilage from trees can affect the signal if a breeze or wind shifts the branches of a tree. Also the PBS black screens, they may have adjusted the transmission data (Ours did for several months) and it required me to delete the digital channel, and then either re-scanning or re-adding it to get it to work properly.

Hopefully, others in your DMA will respond with known problems or solutions if none of what I mentions is applicable.


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## Michael P (Oct 27, 2004)

I had a similar problem that turned out to be a bad COAX connection at the ends of the antenna cable. Did you use all new cable or recycled old CATV cable? If the cable is recycled, all you have to do is replace the ends of the cable. I get great results with the Radio Shack twist-on RG-6 connectors. They arn't cheap ($12.95 + tax for 10 connectors), but they make a good connection and are easy to use.

Be sure your COAX is RG-6 nd not RG-59.


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## Larry (Aug 1, 2003)

gerbildude said:


> I pick up the Sacramento area OTA stations, but I've been having some problems and I'm not sure if this could be 921 flakiness or not.
> 
> When we first installed an antenna everything was good, and we watched OTA stuff without incident for a few months. Then a little over a month ago our Fox station (040-01) went nuts. The normal signal strength is about 90, but it started dropping from 90 to 0 and then back up every few seconds or so, resulting in constant pixellation and sound breakups. I pestered our antenna installation dude, but he seemed confident it was a 921 problem rather than the antenna setup. After about a week the problem suddenly just cleared up, so I let it go.
> 
> ...


I have had a problem with the OTA signal dropping out and then quickly returning, but I had always just attributed it to multipath (which I really don't fully understand...). Yesterday, I was watching an OTA HD program on my 921 and just happened to have the same channel selected on my 811 in the next room. The 921 dropped the signal and of course lost audio...I could hear the audio continue on the 811 (so I guess there was no dropout on the 811). Now, both OTA feeds originate from the same splitter, but the 811 is last in line and so it has more much cable length and a couple of barrel connectors inserted as well. You would think if one of these two boxes was going to lose the signal, it would be the 811. Here's the bottom line...it now looks like this might be a 921 problem instead of an antenna problem. I will be watching this more closely in the future.


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## DalePuckett (Feb 16, 2004)

I believe it's a 921 problem also. In Wichita DMA we have one station that exhibits the behavior you described. It will be strong enough to lock, but only for a few seconds, then it goes back down to zero. Up until about two or three months ago the signal from this station was OK on the 921. KAKE-TV, 10-1, on Channel 21 OTA.

I can put my antenna on my Zenith HDV420 receiver and it is rock solid. The signal strength is not as strong as the other stations, but well above normal. I even tried improving the antenna by installing an 8 Bay deep fringe antenna and I'm only about 10 miles from the station.

It is very frustrating because to watch ABC HD programs, I have to remove the component inputs to my MITS from the 921 and connect them to the other receiver and also disconnect the antenna from the 921 and connect it to the other receiver. Needless to say, ABC doesn't get watched as much as it would if the station were still solid on the 921.

Dale


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## gerbildude (May 27, 2005)

I have tried deleting the OTA stations and rescanning a few times during both these episodes of problems, but it does not seem to affect the behavior. I also think all my current connections are with newer RG-6 cable and good connectors, but I'll have to double check that. It wouldn't hurt to go through and check again to make sure all the connections are still tight.

Multipath/reception problems are always a possiblity of course -- that's why I'm uncertain whether I should call up Dish about possibly replacing the receiver. The PBS signal strength is on the weak end (currently holding at 75) -- however it worked great up until I suddenly lost three of the four feeds. I tend to think there is a receiver problem since one of the PBS feeds is still displaying just fine (006-02), while the other three coming in on the same channel with same measured signal strength are just showing black screens.

Thanks for the suggestions!


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## Michael P (Oct 27, 2004)

Replacing the 921 may not be the answer to OTA reception problems. I had my 921 replaced for the "ZSR of death" bug (lost all my recordings on the HD). The replacement behaved in the same way as it's predecessor as far as OTA reception issues go. I have several stations that will lock but not long enough to acquire. I don't have another model ASTC tuner to compair the 921 to, so I have to presume that the issue is related to the design of the 921's OTA tuner.


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## Michael P (Oct 27, 2004)

> I tend to think there is a receiver problem since one of the PBS feeds is still displaying just fine (006-02), while the other three coming in on the same channel with same measured signal strength are just showing black screens.


 I'd call the station first before blaming the 921 for this issue. I had one station that "went black" despite a constant 100+ signal strength. Doing an "Add DTV" for that station revealed that the channel remapping data was changed by the station. The station engineers are still learning how to set-up PSIP data, when they make changes the 921 does not like, you end up with the situation you posted.


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## Slordak (Dec 17, 2003)

I kind of think the 921 has a software problem which causes some of the drop-outs and pixelation. I sometimes see drop-outs on stations which are consistency running at around 100 signal strength. Even though everything looks fine and the signal strength seems good, all of a sudden the picture will break up, or the audio will drop out for a second.

I'm interested to see if the next 921 software version helps with some of these types of drop-outs, since there's rumor that it may...


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## gerbildude (May 27, 2005)

I think I have this resolved now, but I don't understand why this worked. Tonight I tried explicitly adding the KVIE digital signal by deleting the channels the scan found, and entering the channel manually with "Add DTV". Suddenly I have all four KVIE channels working correctly again (no more black screens).

This just doesn't make sense to me, since the scan had (apparently) correctly found the station and was showing it as an option in the guide. The guide data looks the same now that I have manually added the station, except that now the channels are working.

Strange, but I'm happy to have the stations back!


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## Michael P (Oct 27, 2004)

The station may have updated their PSIP data between the time you did the "Scan DTV" and the manual "Add DTV". Happens here all the time


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## Ainshi (Jun 6, 2005)

Here in Indiana we would have rapidly fluxuating signal strengths resulting in picture coming in and out. We had some local satellite and antenna installers come and checking things out; they replaced some coax combiners and switches as well as re-ended some of the cables, then they replaced the 921 (and we seem to have exchanged a perfectly good 921 for a broken one) to no avail. Finally they sent someone out with a new antenna and a signal reader and installed one in our attic, as opposed to the well-aimed rooftop one, and everything is a-okay.


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