[TenTec] Orion AGC setting for QRN

[Sinisa Hristov]

Steve Ellington wrote:
 
> I just built the little Elecraft signal generator and ran some test during
> high QRN levels. Using a coax splitter, I fed the generator and the antenna
> together into the Orion. The signal was very weak which was perfect for my
> test. I tried various combinations of fast, med and slow setting and no
> matter what, when a burst of QRN hit, the cw carrier was totally blipped
> out. I then went into the prog setting and cranked the decay to maximum.
> This did wonders! No more blipped out CW! So.....For best cw recption in
> QRN, use AGC prog mode, set decay for max. Do not even think about adding
> any hang time!

Reception agains QRN is fundamentally different from
reception against steady backround noise.

Setting decay rate to maximum effectively clips the input signal,
be it CW, noise or QRN. Slightly less distortion should result
from using the slowest decay rate which still recovers from
QRN bursts fast enough. There is no need to use 2000 dB/s
to achive that. As you said, hang time should be zero.

> Threshold level didn't seem to matter.

It should be set just above background noise level,
but if QRN exceeds that level significantly, then
the threshold doesn't matter.


> Interestingly, running the same test on the IC-756PROII revealed no cw
> blipping at any agc setting.

PRO's AGC seems to be clipping at all times,
producing that "dirty noise" sound.


73,

Sinisa YT1NT, VA3TTN