It's all about the Software

The "100%" setting of the squelch scale is quite low compared to where the noise floor can be. On my RSP1A, with a gain setting of 5, IF gain at -35 and AGC off, on VHF and UHF the noise floor is around -80 dBm, which seems to correspond to around 90% of the squelch level. Sometimes it can be above 100% in which case I have to use the Visual Gain setting to artificially lower the noise floor. I don't want to have to do that, especially since Visual Gain is not a setting that can be stored within a favourite. Also it would be nice to have a squelch level indicator on the spectrum display in the form of a horizontal line (that could be enabled or disabled in settings or the View tab).

Please add a full screenshot so I can see your RSP1A in action. 80% seems to be very high.

Here is a screenshot with squelch set at 82% - the setting is low enough for the squelch to turn off:


And here is one with the squelch setting increased to 87% so it works properly:


With AGC on (I need it on sometimes because signal levels vary a lot) it's even worse - gets triggered at 93%:


At certain bands with certain antennas it goes over 100% - with a gain setting that I have observed the best S/N ratio at - which is usually 5 to 7.

The signal levels are very high - do you have a pre-amp?

No, in this case it was just an RH-660S antenna connected straight to the SDR with a right angle connector. The SDR was connected to the computer via 3m long good quality shielded cable with ferrites at both ends, 1 full turn of cable (so it passes through the ferrite twice) on each.

goscickiw wrote: Fri Dec 18, 2020 6:55 am No, in this case it was just an RH-660S antenna connected straight to the SDR with a right angle connector. The SDR was connected to the computer via 3m long good quality shielded cable with ferrites at both ends, 1 full turn of cable (so it passes through the ferrite twice) on each.

Same here on VHF/UHF with my RSP2 and broadband antenna and lots of man made noise ... but when you keep RF Gain as low as possible and lower Visual Gain a bit then the squelsh range is good. 73, Leon