[Orion] Re: [TenTec] Topband: BDR redux

[Grant Youngman]

> We've been enjoying "AGC Treshold" for many decades,
> although we didn't use the name until the recent
> marketing breakthroughs :-)

I think you totally misunderstand AGC THRESHOLD as applied in 
the Orion.

The RF gain control in the less modern receivers you refer to does 
much more than simply change, as a byproduct, AGC threshold.  It 
actually reduces overall receiver gain.  There is no change in 
threshold, only a change in signal levels into the AGC circuitry.

The Orion AGC threshold control is quite different.  The front end 
continues to run wide open (with the 9+30 dB exception where AGC 
is applied to protect the ADC).  The Orion RF GAIN control is 
actually an IF GAIN adjustment -- again, there is no front end gain 
reduction aplied (except for ADC protection).

RF gain, as typically applied, reduces over all receiver gain for 
signals of all levels.  AGC THRESHOLD has no impact on signals 
above the threshold setpoint.  It simply prohibits AGC action on 
signals below the setpoint.

Grant/NQ5T