My K2 s/n 1999 was completed in February 2002.
Last Sunday, during the EC Nets, I noticed that some strong stations were actually getting audio signals into my ears that were close to the threshold of pain. I also noticed they were not "deflecting" the "S" meter one bar. After some experimenting, I discovered that my agc was intermittent. Recalibrating it sometimes brings it back to life. Touching pin 7 of U1 on the control board seems inconclusive for me. I cannot hear the signal on or about 10.136 MHz, but I have been doing this in the operating position while standing on my head on a banana peel with three tools in each hand. Maybe when I get it on the bench I'll be able to hear the signal. At this time I suspect a marginal solder joint somewhere in the signal path from pin 8 of U12 on the RF board to pin 1 of 1 on the control board, or one of the pins on U1 or U12, or a bad crystal X1 on the control board. I intend to do some signal tracing in these areas to see if I can induce the problem one way or the other. (Simply resoldering all of the joints is a last resort; I'd prefer to learn something and identify the exact problem.) I am curious about the S meter calibration process since it sometimes seems to "shock" the system into operation. Can anyone tell me how that process interacts with U1? I am also curious if the collected wisdom of the reflector has seen a similar problem and might be able to shorten my search before I start digging into this. Ed Lambert KD3Y _______________________________________________ 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
