My HR20 occasionally drops some or all OTA channels. It displays "Searching for Signal". A reset always brings the channels back to normal. Does this happen with AM21's also? How do you reset it if it does?
Can you go into Setup on the HR20 and go to Sat and Antenna and navigate to the signal strength screens. I think its in add/remove channels.
Is this a new issue or been there all along?
What's the sig strength of channels exhibiting this behavior? If its 100% then, drops alot and then is 100% again you either have a bad connection or what's known as multipath.
Can guide you further after you provide some more info.
And No, AM21N's do not do this unless there is a problem like multipath that is very severe.