[TenTec] Orion AGC setting for QRN

[Sinisa Hristov]

Steve Ellington wrote:
 
> I ran the test and published the results. 2000 DB/S is exactly where it
> worked best. As a matter for fact 2000 DB/S is the only place it worked.
> Your statement indicates just the opposite. All I can say is "try it". Maybe
> theory isn't always right or maybe QRN is different on this side of the map.


I certainly trust your results and would like
to understand what is actually going on, i.e.,
I'd like to go a step beyond simply following recipes.

Depending on QRN-to-signal ratio, it takes some time
for AGC to restore RX gain after a QRN burst.
For an arbitrary ratio of 40 dB (what's your figure?),
it would take a mere 20 ms to fully restore the gain.
A delay several times as long as that should be
quite tolerable.

What was your frequency of crashes, i.e. ~1 per second,
a dozen per second, or a few per minute?

Therefore, my point was that with the actual (vs. indicated)
AGC decay rate of 2000 dB/s, and everything else unchanged
(AGC attack time in particular), the system is probably too fast.

On the other hand, one may pose the question of accuracy
of the actual AGC rate.  Orion already has some rather
inaccurate selections (AGC threshold, CW rise and fall times,
etc.), so one more is certainly possible :-(


73,

Sinisa  YT1NT, VA3TTN