Um, Joe, he did not say "bring up" as you quoted. Are you certain that by saying "bring to the level" he did not mean bring louder signals *down* to the level of the AF gain? That's how I read it.
Your observation about the best AGC operation is excellent for communications work. Often people have AGC working "backwards", raising the background noise level to room-filling volume when no signal is present. That's how AGC for AM worked, originally, both for auto and home radios. As a station faded, the AGC raised the volume to compensate, keeping the speaker output the same. So, as one was crusin' down the highway listening to The Wolf Man spin tunes on the AM band one might hear the background noise come up in a weak-signal area, then drop down again as the signal regained strength. 73, Ron AC7AC -----Original Message----- >> Remember, the AGC is only supposed to bring things to the level of >> your AF output setting. No. AGC should never "bring up" the level. AGC *REDUCES* the level of signals above the AGC threshold. One normally sets the audio level for signals *at the AGC threshold* or below and AGC keeps stronger signals from exceeding that level (by the amount of the "slope" if one is not using a "hard" threshold). The difference with an *AUDIO PEAK FILTER* is that the APF is in the AUDIO circuit *AFTER* the detector and *OUTSIDE* the AGC loop. Since the PEAK gain of the K3 APF is roughly 10 dB - see the response here: http://n1eu.com/K3/K3_apf.htm - this can cause an issue with strong signal but is a big advantage with signals at or near the noise level (and below the AGC threshold). Of course, the gain is exactly why APF can be turned on and off ... you don't want it on with strong signals - only with those at the noise signals where it makes a difference! 73, ... Joe, W4TV ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
