strange noise floor and rf gain control issue
Posted: Fri Dec 15, 2017 11:07 am
Is the rf gain control simply a visual thing now?
I ask this because I was trying to see the difference between the rsp2 noisefloor as various gain settings. I set theFFT averaging to 1024 in order to smooth out the spectrum display so that I could see what the average noise floor was as max gain. it took a few moments for the FFT sample to get averaged out and for the spectrum to settle. however, when I changed the gain setting the change to the displayed noise floor was instant. like the only thing that changed was the way the spectrum was displayed. I would have expected a delay as the noise floor rose or fell due to the setting change. Is the gain setting actually changing the LNA level and the Gain setting?
I ask this because I was trying to see the difference between the rsp2 noisefloor as various gain settings. I set theFFT averaging to 1024 in order to smooth out the spectrum display so that I could see what the average noise floor was as max gain. it took a few moments for the FFT sample to get averaged out and for the spectrum to settle. however, when I changed the gain setting the change to the displayed noise floor was instant. like the only thing that changed was the way the spectrum was displayed. I would have expected a delay as the noise floor rose or fell due to the setting change. Is the gain setting actually changing the LNA level and the Gain setting?