I put an oscilloscope on the right external speaker (8-ohms) of my K3 and set up on 40M SSB @ 2.7 KHz bandwidth. The audio gain is at 9 O'clock. Band noise is high at S-7, no signals heard. I measured steady state and start-up noise transient voltages. Audio gain is set to Hi.
peak-to-peak noise in steady state is 0.3 volts peak-to-peak noise during start-up transient is 5 volts I compute this as a +24-dB start-up blast, very startling to hear On CW 400 Hz filter I get 0.3 volts and 3.5 volts peak-to-peak or +21 dB start up transient. I believe that a signal or strong band noise needs to be present for this effect to be heard. I went to 10M with S-0 band noise and I can not measure or hear a startup transient at all. So if anyone tries to replicate this problem from a quiet location, better hook up a noise bridge. I believe that someone has noted that the effect has something to do with AGC. I believe this to be correct as I can get the same noise blast by turning the AGC off. AGC settings as follows (I believe all default): AGC Hold 000 AGC PLS nor AGC SLP 012 AGC THR 005 AGC -F 120 AGC -S 020 Mike Scott - AE6WA Tarzana, CA (DM04 / near LA) K3-100 #508/ KX1 #1311 _______________________________________________ Elecraft mailing list Post to: [email protected] 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
