Re: RF Gain & NR w/ RSPDuo
I see a little bit of a problem here. On 40 meters the RF Gain control cannot change the actual SNR due to all or most of it coming in on the antenna wire. And as a practical matter I've seen a front end that actually developed a lower noise figure with increased AGC action It had other defects that made it undesireable. So I am not sure what effect you are experiencing on your transceiver.toggle quoted messageShow quoted text
That said on the left you will see an AGC tab. Click to expand it. Then click the off button. The "Gain" slider then behaves like an RF gain control. But it will behave the same as the audio level control for SSB and CW. For AM you may see a difference. I suspect it will not be big. Note that an SSB or CW receiver without AGC is basically a direct frequency conversion to audio frequency from RF with filters and no other audio conditioning. So going from maximum gain downwards can only increase the noise level relative to the signal level.
In general you get the best SDR or ham transceiver performance with the gain set at the point the signal to noise stops improving with increased gain. You can increase the gain usefully until you see spurious signals more or less explode onto your spectrum display. You cannot do better usefully.
On 20210722 09:28:06, n6vl via groups.io wrote: