Re: [TenTec] guide to adjusting Orion receiver; filters and performance

[Sinisa Hristov <shristov@ptt.yu>]

Carl Moreschi wrote:
 
> I ALWAYS run my agc threshold  at 0.37 uv and RF gain full.
> I cannot find any example of an improved signal to noise ratio
> by either reducing RF gain or increasing AGC threshold.

Maybe you didn't increase the threshold sufficiently.
Please note that AGC THRESHOLD values are in error
by whole 21 dB with preamp on (9 dB with preamp off).
So, you probably didn't get the threshold level you aimed for.

The effect to look for is the reduction of distortion
caused by a weak signal and noise modulating each other
through AGC action. This is noticeable even with the
slowest decay setting, but, of course, vanishes with
a long hang time, which may not be acceptable for other reasons.


73,

Sinisa  YT1NT, VA3TTN