dvdesolve/glrpt

Automatic AGC isn't regulating to correct level?

Opened this issue · 1 comments

Hi all.

After a couple of weeks of frustration, using lrpt and other software (and combinations) without any luck, in one of those moments, I decided to change the AGC in lrpt to manual and experiment:

  • Putting the gain too high unlocks the PLL - that's not good...
  • But lowering the gain slowly, suddenly lrpt started to decode furiously. Never had anything more than one or two packets with auto-AGC... Tens of packets seemed a serious improvement ;-)
  • Waited for the next orbit, and started where I left off. Immediately I started collecting packets and collected hundreds (1800+)

So, I suspect that the AGC is regulating too low: I believe the auto-AGC was at about 33, but decoding really started around 44 (till about 56).

Is there any way to get the auto-AGC to regulate to another level?

IIRC, I've faced the same problem in the past. it looked like auto agc gives much more gain than manual. in my case it was ok because SNR was quite optimal and even huge gain didn't spoiled it. it seems like auto and manual modes of agc in rtlsdr driver are implemented different