- what is the problem with hardware AGC?
- why isn't software AGC used?
- Does changing the gain cause a disruption, or can the gain be changed at any time in the C++ libraries?
I am interested in making an aviation receiver for a single frequency. The software I have looked at does not implement any AGC function (rtlsdr_airband and rtl_fm). ...airband has AVC (AGC on the audio) but does not adjust RF gain. Also, neither turns on the tuner AGC.
So, what is one to do? The dynamic range of the dongle is not as good as it needs to be without AGC. In my application, I would rather have intermod and blocking than no AGC, but the signal of interest may range from very weak to very strong.
My testing shows that at high gain, strong signals become unintelligible - no doubt due to clipping either in the analog circuitry, or exceeding the ADC range. At low gain, of course, weak signals disappear.
Thanks in advance.