Apache Labs Community Forum

Can someone explain the S-ATT behavior?
Running 2.8.11 and turn up S-ATT from 0-31 the signal level on both the SMeter and the spectrum goes up with it.
Not logical to me at all. How does S-ATT attenuation affect signal level? And we've talked about the SMeter in Thetis to be accurate -- which means it should NEVER change based on attenuation or gain functions and should always show the signal at the antenna.

Signal levels on the panadapter and the S-meter do not change with changes in S-ATT (or the regular ATT, either). See the second post here: https://apache-labs.com/community/viewt ... f=6&t=2463

"Why the S meter and panadapter don't change readings when you change the attenuator setting"

However, when you increase attenuation, system noise figure (NF) also increases. With enough attenuation cranked in, the degradation in NF will start to become visible above the noise floor coming out of your antenna and you will see the noise floor increase on both the panadapter and the S-meter but signal levels will largely remain the same.