W4BXI Test of 5 Antennas

Here is a screen shot of audio recorded at about 0835 CDT at my receiver during W4BXI's test of 5 antennas on 3740 kHz. The total time duration is just over 50 seconds. Today I had the RF gain set to max, where the S-meter readings are most 'accurate'.  Yesterday I had it set some amount below max during the audio recording. Having the RF gain at max may alter the receiver's AGC action and resulting amplitude comparisons. I note that the background noise rises in amplitude before each tone transmission starts.For future audio recordings I'll make a point of reducing the receive RF gain.