On Sat, Feb 17, 2024 at 07:58 PM, Hans Summers wrote:
Yes, you are correct. But this is also how I have declared that the system works. If you look in the operating manual section on the AGC I described all the stages the signal goes through from the antenna BNC port through to the 3.5mm earphone output. You'll see that I said the band configuration gain value comes before the AGC action. The audio attenuator and volume control gain come later. This is why they don't affect the S-meter. So the intention was that the band configuration gain can be used to equalize and calibrate, to cancel out any differences in BPF attenuation etc between the bands.?
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On my unit a band configuration gain of 54 on 40m calibrates the S-meter correctly. Note that the S-meter is logarithmic with 6dB/bar. This doesn't depend on anything in band configuration, it's linearity as 6dB/bar is always accurate. But the number of bars for a given level such as S9 would vary and that's what needs calibration by adjusting the gain in the band configuration screen.
Thanks, it's clear to me now. I read the AGC section in the manual (very nice, btw) but I was under the (wrong) impression that the system somehow would compensate for the audio gain setting in order to keep the calibration. Reading you post, I think you have a good point, with a sig. gen. one can manually set gain per band and end up with a nice S-meter all across, unlike some top brands which shall remain unamed :-)
So thanks again for lifting the fog :-)
Regards,
YO3GFH
op. Adrian
