Hi group! I have just finished the alignments and tests (part II) in my (second) K2-project. Sofar all resistance checks are ok, and the results of the alignment and tests have also been ok. Except for one thing: I think that the AGC in the radio behaves rather strangely. It's pretty nervous in the "Fast" position and switching to slow makes it a little bit better, but not perfect. I have also noticed a "chuffing" or "clicking" sound in my heaphones while tuning the radio aound on 40 metres. This sound (which indeed is very difficult to describe) corresponds with the change of digits on the display (regardless of tuning rate) and is very significant with the appearance of a strong signal. Tuning the BC-band above 7100 KHz is very annoying. The behaviour disappears when the antenna is disconnected, but occours again when connecting a signal generator or other RF-source to the antenna jack.
Measuring the AGC-treashold voltage on pin 5 of U2 (control board) gives a range from 2.65-3.74 volts when adjusting R1 from counter-clockwise to clockwise. The recommended voltage is 3.80 volts, which I never reach. I've checked the control board very carefully, looking for solder bridges, cold solderings, incorrect components etc, but everything seems to be fine. I've even re-heated all solder joints on the control board without success. Any ideas, anyone? Regards, Hans, LA2MOA K2 #6341 - unfinished _______________________________________________ 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
