V3.3 Issue

[Max]

@Max
See #5

Ah, Nooelec RTL-SDR. Sorry, missed that one. Not sure then.

The way I calibrate Visual Gain is to have no antenna connected then adjust visual gain for zero S-Points on the received noise floor.

If you do this in both V3.2 and V3.3 do you see a difference in the Visual Gain setting required? My guess is it will be this and the difference is not due to actual signal reduction but some change to the calibration of the Visual Gain introduced by a processing change between versions. V3.2 is now many many months of programming and a huge number of changes behind V3.3. Maybe Simon will comment if he can remember changing anything that would affect the Nooelec Visual Gain setting?

73

Max

[jdow]

Hm, I missed that reply. It was so short I overlooked it. Ah well.

Yes, there may well be gain changes in the dongle setup. Use 3.3 and forget 3.2. Because of the newest rtlsdr dongles 3.2 and 3.3 use different rtlsdr.dll files. This may look like a different front end to the two program versions. You may need to set 3.3 gains. Start with a high gain and reduce the gain until a week signal's SNR jumps up. Back off one reduction and you're at about the best gain setup. Because of the way visual gain works on SDRC I am not sanguine about varying that gain. YMMV. (Simon applies the gain by multiplying incoming dongle data by visual gain. That can lead to internal overloads. The "right" way to apply a "visual" gain is simply to multiply values to be painted on the screen just before the log is taken and the position on the screen is calculated or the text on the screen is calculated. It's more code. But it does not intrude on any of the signal processing. IMAO - Simon'sMMV)

{^_^}