Larry,
Since you asked 'why' - U2 pin 13 connects to the "D2" button encoding
line - the buttons that use this line are BAND+ and the AGC/CW REV
buttons. Any unsoldered connection along any point of a signal line
will cause the same behavior (one must connect all ends of the wires,
even if the wire is actually a PC board trace).
If there was a slight contact between the pin and the solder pad, it
would likely work sometimes. Such is the nature of unsoldered
connections. I have seen them work for years and then suddenly develop
enough oxidation to stop working.
73,
Don W3FPR
L. D. Ingram wrote:
>
> Hi,
>
> I received a note from Don W3FPR and Hank K8DD about the problem I
> posted the other day where even when I just tapped the band up button
> on my recently built K2 it would sometimes go into the RCL mode.
>
> First I want to say thanks for the suggestions and then tell you what
> I found in case someone else has this trouble. It was the usual, a bad
> solder joint, but not where you would expect it. What happened is U2
> pin13 was left floating because the trace from RP1 went through the
> common terminals on the AGC switch and one of those was not making a
> good connection. Once I got voltage back on pin 13 of U2 everything
> worked. The puzzling thing is why it worked most of the time with that
> pin floating.
>
> Thanks again.
>
>
_______________________________________________
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.htmElecraft web page:
http://www.elecraft.com
Locked
