AM21 dropping channels

[Hay997]

I have the HR21-100 along with the AM21 for local channels. I've had both boxes since August 2008 and have had no problems with them. I live in the Mobile, AL DMA and receive the major networks plus one other channel.

Within the last couple of weeks, I noticed that my NBC local channel was no longer coming in. I talked with the affiliate and they told me that they haven't done anything in the way they are broadcasting.

I pressed the reset button, it rescanned everything, and still that one channel didn't work. I unplugged the boxes completely, did a complete setup, and everything worked. After 2-3 days, that same channel dropped again. I did another hard reset, it worked, then the same channel dropped again. Now, 2 of the channels are dropping. I did an initial setup again and even though I am putting in the correct zip codes, the box gathers data from Anchorage, AK, along with the correct channels.

Has anyone else experienced problems with the AM21 dropping channels for no reason? Is this a problem with the box? I can't figure out anything else to do.

[litzdog911]

Check your off-air signal readings for those channels. What do you get?

[JimSpence]

Do you have a clear line of sight toward your local towers?

Are the trees starting to leaf out? It's possible that you might be having multipath problems.

Did any of the stations do the digital cutover early? And may have changed frequencies?

[tomtahoe]

I had the exact same problem with my AM21. I had DTV tech come out and they have no clue on these. I had another one sent to me and it did the exact same thing. I ended up switching to HR20 with built in OTA tuner. Still having the same problems with it. I don't think DTV knows how to build a good OTA receiver. I hooked up one of the digital tuner boxes to my outside antenna and get perfect reception. DTV has crappy OTA tuners!

[litzdog911]

tomtahoe:
It's always been true that the DirecTV off-air digital tuners are not as good as some of the tuners used in TV's or stand-alone converter boxes. But that shouldn't prevent the original poster, and you, from trying some of the standard off-air troubleshooting tips that we try to provide. Often simply tweaking the antenna position or location can make all of the difference.

[tomtahoe]

I did not have to do anything to make the $20 OTA digital tuner work perfectly with the same exact same antenna and connection. DTV OTA receiver should work just as well when you have to pay so much for their service and we are "loyal" and "valuable customers". 2 AM21 and an HR20 all do the same thing. Not too impressive to be pushing this junk on us.

[JimSpence]

Here's my OTA story.
Distance from towers = 9+ miles
Hill between me and the towers preventing the use of a small antenna.
I ended up with the Winegard 7084 monster with preamp.
Local channels using frequencies, 4, 7, 8, and 42.
Mounted the antenna on the peak of my single story house near the southern end. (~ 25' from ground level).
Signals were very spotty (multipath problems).
Moved the antenna about 30' to the north, still on the peak.
Signal levels are vastly improved, yet not perfect.
I have since removed a couple of tall pines that were in direct line to the towers. This made things a bit better.

My worst channel is the one on ch4, which will revert to its original frequency (34) once they get their transmitter update.

Bottom line is that location is very important. And it isn't always the tuner's fault.
For tuners, I have the HR10-250, HR20-100, HTL-HD, and an LG LCD TV.
All of these have varying success.

After the cutoffs, I plan to tweak the antenna and hopefully can get near perfect reception.