Once in awhile I run with the AGC off, usually under extreme
conditions like 80m at night with weak signals and heavy QRN static
crashes from distant thunderstorms.
The reason we used the old way originally was that only the most
expensive receivers had AGC that was IF or audio derived. The rest
had AGC which rectified or detected the signal envelope. If the BFO
was on, it would look like a carrier to the AGC rectifier and would
produce a big AGC voltage which would cause a reduction in receiver
gain.
73, Bob WB2VUF
Jim Reid wrote:
>
> Hi,
>
> How many of you, when on CW, run the "old" way:
>
> Turn the AGC OFF, with the RF gain backed off, and
> with the audio turned full up. That's the way we did it in
> the old days using the tube rigs. You adjusted the
> "loudness" of the signal which you listened to with
> the RF gain control.
>
> Benefit of this method is/was to keep the noise level down,
> now however, with the OmniVI+, with the in-built, IF filters,
> combined DSP and CW audio peaking, I find the "old"
> way not that useful anymore. Any still using it? If so,
> why, or under what circumstances, perhaps because
> you don't have DSP or APF, hi.
>
> 73, Jim, KH7M
>
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