Thanks Ron, problem solved.
I checked U9 Pin 7 and found 13.35 vdc. Found no shorts around the headphone jack. Checked orientation of C32 and C33, OK. Checked U10 pin 4 and fournd 7.94 vdc. I reheated all solder joints on chips and jacks. I think the problem might have been a solder joint on one of the jacks. Now I can blow my ears off before I get to st L 100. Thanks again. Terry VA6Mac -----Original Message----- From: Ron D'Eau Claire [mailto:[EMAIL PROTECTED] Sent: Wednesday, March 14, 2007 2:43 PM To: McMillan, Terry; elecraft@mailman.qth.net Subject: RE: [Elecraft] K2: st L How loud? Since you can change the frequency and can hear something, the places to look are the AF Amp, U9 and sidetone source Q5/U10B. I'd start at the AF amplifier and make sure +12 is present at pin 7. If so, next I'd take a close look at the soldering. Did you miss a pin? Is there a short? A common place for a short seems to be around the headphone jack pins on the board. Next, are electrolytic capacitors C32 and C33 oriented correctly? If reversed they could ground the input of U9 or the output of U10B for d-c through L1. Do you have 8 VDC at pin 4 of U10? That's required for the sidetone "driver" to provide the correct levels. Ron AC7AC -----Original Message----- Thanks for the reply Ron, I also tried a set of iPod earbuds with the same results. Terry VA6MAC ************************************************************************ This e-mail message is intended only for the person(s) named above and may contain confidential or privileged information. If you are not the person named or have not been authorized by them to access their mail, please notify the sender immediately and delete this e-mail and any attachments without reading, saving, or forwarding. ************************************************************************ _______________________________________________ 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
