Gerald, That certainly sounds like it might be hard to isolate. I may be wrong, but from the behavior it sounds like you have a relay with points that are not making good contact - when you put a bit of RF through it, it becomes OK for a while. Please be aware that this is just speculation on my part. You may have to work with it a lot to determine if it is really fixed. Intermittents are very difficult to troubleshoot.
Before you do anything drastic, check for unsoldered connections in the bandpass and lowpass filter areas and the T/R switch too. Sometimes unsoldered connections will work just fine for a long time but afterward they begin to develop oxidation which makes the connection first intermittent and then perhaps fails completely. The connections for these areas are under the heat sink, so be prepared to remove it for your soldering checks. If you can induce the failure and then have it continue while you remove the heat sink, you could also check the relay points with a continuity test between the pins. Check the schematic key for the realy chart and the schematic itself for the appropriate relay points and pins. You should be able to receive with the heat sink removed, but be certain you do not attempt to transmit until it is replaced - WORK CAREFULLY if you attempt power on with the heat sink removed. 73, Don W3FPR > -----Original Message----- > > Hi all > I notice an intermittent rx sensitivity on my K2, Serial-Nr. > 488, after changing band eg. from 20 to 40 and vice versa. After > pushing tune or transmitting a couple of dots the sensitivity > returns > on the activ band and is gone on the other band. This happens with > and without the KAT2. > > Where shall I start searching? > > 73 Gerald, HB9CEY > _______________________________________________ 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
