RF Gain control on SDR-Console V3
Posted: Sun Jul 29, 2018 2:38 pm
Apologies if this has been asked before but searched and cannot find as the bulk of users here seem to use SDR Uno, so to be clear it's SDR-Console V3 I'm asking about, and receiver is SDRPlay RSP2Pro.
With no antenna connected to any input and with antenna switch select to Input A or B, IF gain set to manual -35dB, AGC 'off', and visual gain set to 'zero', adjustment of the 'RF Gain' control seems to work exactly the opposite way around to how it is labelled.
So, with above settings, when the RF slider is set to 0 (labelled 'max') the audible and visible noise floor is at minimum and on the pan display noise level is about S0, and with the slider set to 8 (labelled 'minimum') the noise floor shoots right up to around S7, and predictably in stages at every setting in between, 1 to 7, however there is a larger 3 S point jump up in noise between setting 7 and 8 than between the lower settings.
This would seem to indicate to me that position 0 (labelled 'max') is in fact minimum gain (or I would guess 'zero' gain as the noise floor is almost exactly on S0 on the pan display) and position 8 (labelled 'min') is in fact max pre-amp gain?
Can anyone from the SDRPlay design team please confirm is this correct? I asked on the SDR-Radio forum but nobody came back with the definitive answer including Simon Brown. At least one person was convinced it is the other way around, but I can't see how that can be so given the behaviour of the noise floor as described above with IF gain set to manual and no AGC?
Anyone know for sure?
Thanks, Max
With no antenna connected to any input and with antenna switch select to Input A or B, IF gain set to manual -35dB, AGC 'off', and visual gain set to 'zero', adjustment of the 'RF Gain' control seems to work exactly the opposite way around to how it is labelled.
So, with above settings, when the RF slider is set to 0 (labelled 'max') the audible and visible noise floor is at minimum and on the pan display noise level is about S0, and with the slider set to 8 (labelled 'minimum') the noise floor shoots right up to around S7, and predictably in stages at every setting in between, 1 to 7, however there is a larger 3 S point jump up in noise between setting 7 and 8 than between the lower settings.
This would seem to indicate to me that position 0 (labelled 'max') is in fact minimum gain (or I would guess 'zero' gain as the noise floor is almost exactly on S0 on the pan display) and position 8 (labelled 'min') is in fact max pre-amp gain?
Can anyone from the SDRPlay design team please confirm is this correct? I asked on the SDR-Radio forum but nobody came back with the definitive answer including Simon Brown. At least one person was convinced it is the other way around, but I can't see how that can be so given the behaviour of the noise floor as described above with IF gain set to manual and no AGC?
Anyone know for sure?
Thanks, Max