With the new firmware, I found it necessary to do the S-meter calibration. This restored the previous "base" behavior.
Not sure what the state was before the calibration, whether I had done the prior calibration correctly, etc., so I can't "blame" the firmware. My guess, though, is that I'm on a learning curve, and only the latest, most informed thing I have done can be trusted, if that. Afterwards, if your noise goes from S nothing to S5 by attaching the antenna, you surely are in a noisy locaton. If so, turn off the preamp and/or use the atten to reduce the "resting" gain of your RX. After that just turn your RF gain counter clockwise until the resting noise in the RX is something you can live with. I've had to do that all summer long, as 40 and 80 meters have had nasty QRN nearly continuously. Beyond that, reducing bandwidth on CW, the K3 has been able to listen down into the noise in a way unrivaled by any other RX I've used, including the Orion. Of late for CW QSO's, once established, I center their signal, and go to 50 Hz bandwidth immediately. No reason not to, and the bandwidth drops the noise way down. If they are above the noise, tuning just barely slightly off their signal removes just enough softness in the signal to make it quite pleasant. 73, Guy. My K3 #1263 was delivered in July with F/W MCU 2.18 DSP 1.84 and I was really enjoying the RX capabilities of the K3. Now that I have upgraded to 2.38/1.90 I believe the RX is more "restless" when listening to an "empty" space on the band. The S-meter is constantly on S5 with pre-amp ON and S3 with pre-amp OFF on the lower bands (30/40m). I have compensated that a bit by lowering the AGC threshold (from 5 to 4 now). I liked the initial F/W wrt AGC behavior better (less fatiguing to listen to). I have read in the F/W history file that changes to the AGC have been made from F/W 2.22 onwards. So I wonder if other people have the same experience. I live in an urban area so it IS noisy out here. It is just the way the K3 deals with that noisy background level. When switching to ANT2 (not connected to anything) the RX goes virtually silent. -- Enno, PF5X -- View this message in context: http://n2.nabble.com/AGC-behaviour-tp1114728p1115351.html Sent from the Elecraft mailing list archive at Nabble.com. _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
