I'm guessing this "effect" is an artifact of the AGC parameters and the level of ambient noise. I would love to see a chart of AGC level, K3 gain, and RFG bias voltage.
I see a flat zone between RFG at maximum and at 3-o'clock position when I either have no preamps activated and when I activate the PRE (internal preamp). Gain appears flat over that range and I hear no change in audio level with antenna connected. Remember that I have extreme hearing loss so it may mean I unable to hear the change even if there is one. When I run my ARR preamp, the s-meter indicates S4.5-S5 and the s-meter immediately rises when I rotate the RFG to a lower setting. There is no flat region. Since my preamp has 24-dB gain and K7WIA is using a preamp with 15-dB gain, they are not exactly compariable. The approx. 9-dB extra gain may be saturating the follow on Rx circuits. A precise measurement of SNR (with a weak signal) vs RFG voltage would be interesting. Perhaps Eric or Wayne will comment. 73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 50-1.1kw?, 144-1.4kw, 432-100w, 1296-60w, 3400-? DUBUS Magazine USA Rep [email protected] ====================================== ______________________________________________________________ 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
