[Elecraft] The Good News and the Bad News - A Major War Story

Thu Jul 10 21:29:05 2003

Dear Elecraft Fans,

First, the good news.  I have just graduated to page 75, "Final =
Assembly"!  It actually was a lot of fun, with the possible exception of =
the bad news which may turn out to be fun, too!

I'm gonna sue!  I'm gonna sue for damages and mental suffering.  I'm =
gonna sue!

I just spent the best part of a lifetime - at least eight hours - trying =
to figure out why my power amplifier wouldn't work.  The problem was =
isolated reasonably quickly to the fact there was no bias from the bias =
amp when transmit was turned on, as noted in a previous posting.  Parts =
measured OK.  I even re-wound T2.  It seemed the most likely to have a =
winding problem.  I wasted Q11 and Q13.  I replaced them with known good =
2N3904's I had.  I also wrecked U2 in that process because of stupidity, =
and not paying attention to what pads I was working on when looking at =
the back of the board.  So I ate a 78L06, too!  (Lisa is gonna send me =
another one.)

I decided to drop back to basics.  I tried to measure continuity from =
the emitter of Q13 to the bases of power amplifier transistors Q7 and =
Q8.  Open circuit was the wrong answer.  But that meant something was =
wrong with the PC board!!!!!!!!!!!!!!!!!  At last, I was almost at the =
end of the diagnosis!  There is a little plated through near the emitter =
pad for Q8.  It WASN'T PLATED THROUGH!!!!!!!!!!!!  I stuck a clipped off =
lead through the hole and soldered both sides.  Guess what?????????????/ =
 I had power amplifier bias, and a 15 plus watt power amp. too!

Now, all is well.  I have a working basic K2  I feel great!

There is one thing to note of a serious nature here.  I hadn't =
considered the number of little plated through holes (we HOPE they're =
plated through) in the boards.  Normally, in a wave soldered process, =
the holes are filled by default.  In hand soldered stuff they may or may =
not really be plated through.  It seems unreasonable to add checking =
each hole before loading.  But it's obvious we need to consider the =
possibility when trouble-shooting.  It literally was the last thing I =
would have expected. I seriously considered sending it back for repair.  =
It would have cost me a fortune, unless the Elecraft guys have seen bad =
pop-through holes a lot before.

Manufacturing defects happen, and in places where ordinary inspection =
probably doesn't reveal well.  Special board tests requiring expensive =
tooling can weed this stuff out.  It also helps put neat little radios =
beyond the price range many can afford.

Now for the law suit.  I guess I'll let Elecraft set the terms of =
settlement.  Enjoying my radio is probably about it!

Now, If I could just get my antenna in the air.  That's about to become =
the critical path toward QSO's.

73

Bill
NA7Y

--- 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  ---