Bill Tippett wrote:
> >AGC DECAY can be kept at 5 dB/s with AGC HANG time at 0.30 - 1.00 seconds.
> This minimizes AGC-induced interference with signals at noise level.
> Very interesting Sinisa. I have not played with such high settings
> of Hang and played with this on some very weak signals on Topband
> this morning. Based on my limited use, it does seem to help. Could you
> explain the theory behind this? I suppose it simply slows down the AGC
> action to the point that it does not raise the noise level between CW
> characters.
AGC is inactive during "hang" time with gain held at fixed level
determined by the signal peak at the start of "hang" time.
Benefit is twofold:
* constant gain eases the job of our neural system, in part by not
raising noise level between characters/word, as you mentioned;
* the usual AGC-induced intermodulation is avoided
(AGC action essentially multiplies the signal with a rectified
and filtered version of it, creating intermodulation
which is particularly bad with a signal at the noise level).
I'm glad to see that my posts may be of some value.
73,
Sinisa YT1NT, VA3TTN
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