[Elecraft] [K2] Lost 80m recieve.

[Alan Davenport]

Don,
 
    No, the relays are not damaged. I was extra careful with them as the build instructions said to be. 
 
     I just re-flowed the solder on C72 and all K13 pins. The rig is now working on all bands and the VCO is in spec on all bands EXCEPT 80m. 80 was working briefly and just quit as I was typing my response. I switched bands and when I switched back to 80 it was dead again. Direct frequency entry does not help.
 
I  think I had two seperate issues. 80M had been dead since I was away on vacation this June and the other bands were working fine. I do not know when they went dead but I do know I spent 7 weeks at a remote cabin and I used the K2 extensively on all bands up there. 80 went dead while I was there. (3 days after I put up a dipole to get on a net!)
.....
 
I just took it apart again, I reflowed the solder on all relays for 80m, K2,K3,K8,K13 and also K14 & K15 as well while I had it apart. 80m is currently working as are all other bands. I have switched bands many times and 80m continues to work. Looks like I may have fixed it with your help. As always Don, thank you very much for taking the time to help me and everyone else who asks for help.
 
    Take care,
  Al, W2GZN
From: Don Wilhelm <w3fpr at embarqmail.com>
To: Alan Davenport <w2gzn at yahoo.com>
Cc: "elecraft at mailman.qth.net" <elecraft at mailman.qth.net>
Sent: Tuesday, September 6, 2011 9:34 AM
Subject: Re: [Elecraft] [K2] Lost 80m recieve.

Al,

With that new information, I can say that the problem is in the VFO Range Selection area.  It could be relay(s) or it could be capacitors.  Do you have soldering iron burned cases on any of K13, K14 or K15?  If so, those relays should be replaced since that is the most likely problem.

If the relay cases look good, then it is time to measure the relay contacts with your ohmmeter.  Use the schematic (RF Board sheet 2 to determine the pins associated with the set and reset state of the relays - they are shown in the reset state.  Then switch to each band and consult the chart at the upper left of the Schematic Key page to see which of relays K13, K14 and K15 are set for that band.  Confirm with your ohmmeter that there is continuity between the correct pins of the relay.  Continue for other bands until you have confirmed that the proper relays have been set, and also check that those which are supposed to be reset are actually in that state.

It is also possible that you have a bad output from the I/O Controller and the relay is not getting the pulse to set, but that is a rare occurrence.

73,
Don W3FPR