Thank you for various replies. For others who may have the whining power supply problem with these, here is the answer.
It turns out that one group of these power supplied were made with an incorrect value at R25, found on the bottom of the board. Installed is 2K ohm which is clearly marked, and it needs to be 2.7K ohm. After making this change, the recharging whine in the headfones is gone. Took about an hour to work the board loose of the chassis, make the part change, and put it back together. Now working perfectly! Runs a K2/KPA100 like crazy. thanks folks, 73, Fred - kt5x _______________________________________________ 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
