Re: ALC Overrun


Frank, G0GSR
 

Algenon,  I don't have a 7100 to check but I very much doubt that you have zero power overshoot, on SSB due to ALC action, although CW maybe just fine.

I think that you need a digital storage scope to capture it as the power overshoot maybe just 5mS duration (as in the case of the IC-7300).
You also need to view the ALC "working" by allowing  the gain to completely recover, then hitting it with a peak of maximum level.

I have done some tests, on SSB with pulsed tone, allowing 4s after each for the ALC to recover.

On my IC-7300, at low power levels, the ALC induced power overshoot was around 2dB but strangely on 4m, the power overshoot is much worse..
At higher power levels, gain compression in the PA reduces the overshoot but those brief "over-drives" don't help with the general crud that surrounds most signals.

Frank

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