[Elecraft] Strange Behavior Elecraft K2

Fri Feb 28 20:40:00 2003

James:
  As a quick test, remove the bottom cover (front section only) and cut a 
piece of paper the same size.  Replace the cover with the paper between the 
inside of the cover and the electrical guts.  If the problem continues, 
there is something weird; if the problem goes away, there is almost 
certainly something touching when you squeeze the bottom cover.  I should 
think some careful inspection would locate the spot -- else, give Ron's 
suggestion a try.  [nB: Be sure to remove the paper when through.]

best wishes,

dave belsley, w1euy

--On Friday, February 28, 2003 4:28 PM -0800 Ron D'Eau Claire 
<[email protected]> wrote:

> I suggest pulling a side cover and, using a good light, carefully
> checking for any leads that might be touching the bottom cover when you
> squeeze it. Depending upon which part of the bottom cover you are
> squeezing (the back part with the PA transistors or the front section
> where the stand is mounted) you are flexing one end or the other of the
> r-f board, either through the r-f transistor mounts or through the BFO
> choke mounting.
>
> If you don't have anything touching the board, you have found an
> intermittent. An unsoldered joint, or a 'broken' joint or even a broken
> trace, although unless the radio has been really "savaged" at some point
> a cracked trace should be very unlikely.
>
> If I can't see a short, my usual approach is to get a No. 2 Pencil with
> an eraser on the end (an "HB" might work too, but for me a No. 2 is a
> better Mojo - the eraser is the REALLY important part) and, using the
> eraser end, try pressing the eraser on various parts of the board with
> it from the bottom or pressing on various components from the top. Be
> gentle with toroids or anything on leads so you don't crush them or
> break a lead.
>
> If you are lucky, you will discover a component that causes the symptoms
> to appear with only a little pressure. There, you will find a bad
> connection or a short. If it's an unsoldered connection, you won't be
> the first op by a long shot who got a couple of years of FB performance
> from a K2 before it showed up!
>
> Ron AC7AC
> K2 #1289
>
> -----Original Message-----
> I've had my Elecraft working for some time, but I encountered something
> strange just last night. When the rig was on, I picked it up to move it,
> I placed my thumb under the bottom near the middle. Next, I noticed the
> radio static dropped out, and all the leds on the S-meter lit up. I
> thought this might have to do with a short on the PA transistors, so I
> checked those out, even applied new thermal pads. Everything seems to be
> okay there but I still notice this strange behavior if I put a slight
> amount of pressure under the radio. Has anyone had this happen? Any
> suggestions?
>
> James De WL7NO
>
>
> --- StripMime Report -- processed MIME parts --- multipart/alternative
>   text/plain (text body -- kept)
>   text/html
> The reason this message is shown is because the post was in HTML or had
> an attachment.  Attachments are not allowed.  To learn how to post in
> Plain-Text go to: http://www.expita.com/nomime.html  ---
> _______________________________________________
> Elecraft mailing list: [email protected]
> You must be a list member to post to the list.
> Postings must be plain text (no HTML or attachments).
> See: http://mailman.qth.net/mailman/listinfo/elecraft
> Elecraft Web Page: http://www.elecraft.com
>
> _______________________________________________
> Elecraft mailing list: [email protected]
> You must be a list member to post to the list.
> Postings must be plain text (no HTML or attachments).
> See: http://mailman.qth.net/mailman/listinfo/elecraft
> Elecraft Web Page: http://www.elecraft.com

----------------------------------
David A. Belsley
Professor of Economics