K2 Receiver Instability

[Todd Fonstad]

My K2/100  #1130 has developed an odd instability. When first turned on, the
receiver seems unable to "lock on" frequency, so that CW signals have a
warble to them. After a few seconds to a minute or more, the receiver
stabilizes. The instability returns after each band change and often occurs
when I change the XFIL setting. I don't know if this condition manifests
itself in the transmitted signal.

I need to take the unit apart to check mechanical/electrical connections
prior to my using it as my mobile rig in the Wisconsin QSO Party this coming
Sunday.

Do any of you kind souls have an idea where I should concentrate my
trouble-shooting efforts? I receive postings in digest mode, so direct
e-mail as well as posts to the reflector would be most appreciated.

I'll endeavor to inform the group of the outcome.

Best regards,
Todd
N9NE



_______________________________________________
Elecraft mailing list
Post to: [hidden email]
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

[Rich Lentz]

My best guess is that you neglected to solder a pin or have a cold solder
joint on U4 - the PLL synthesizer.  Quite often an un-soldered pin will work
for a year or more, then oxidation causes it to go intermittent and then not
work at all.  Check solder connections for the parts on the top half of
sheet 1 of 4 of RF Board.

Next I would check voltages and that should give you an idea of where there
could be a problem.

Rich,
KE0X

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
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