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

[Marijan Miletic, S56A]

YT1NT> Internal (AGC) mechanism is immaterial.

Analog AGC (it should actually be AGR_eduction) has a fixed parameters and
its main function is to prevent DSP A/D input overflow.
As long as this is under control, digital AGC can do all the math wonders of
system theory with CPU memory help.

YT1NT> DSP noise reduction acts similar to your description, but it is based
on
selective and adaptive filtering, not on simple gain change. And it works
only with signals strong enough to be distinguished from noise in short
time.

DSP noise functions are based on long time recursive routines dealing mainly
with repetitive cyclic signals versus random amplitude/frequency noise.

YT1NT> All the fuss is about preventing AGC to interfere with weak signal
reception.

This is done on statistical basis while hams prefer unique propagation
cases!
AGC is supossed to be A_utomatic and NOT manually controlled...

73 de Mario, S56A, N1YU