[Elecraft] Can't hear the internal birdie while in CW

[Ron D'Eau Claire]

 -rob N7QT
What should I be reading between the leads and the case? I'm measuring
about 237K between them.
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Hi Rob:

I would have expected to see something down in the fraction of an ohm if
a crystal lead was shorted to a case. 

The fact that your SSB filter seems okay, (the loss of sensitivity is
only in CW, right?) would point to a problem in the CW filter setup on
the RF board, but you did not mention exactly what "other" mods you put
in just before the problem was noticed. Are all the crystals in the i-f
filter on the RF board soldered correctly? No missed leads or no shorts
in that area. That would be X-7 through X-11. 

If one of the other mods you did was the "2nd Xfil Flattening Mod", it
could be causing a problem. It's switched in and out with the SSB mode
selection, and a mistake there could be causing a loss of signal in CW
modes. 

If I were in your shoes and could NOT find anything wrong with my mods,
I'd consider pulling them out ONE AT A TIME and checking for restored
normal operation after each mod is undone. Start with the easy mods
first, like the 2nd Xfil Flattening mod, if that's one of the ones you
put in. And don't just disable it, REMOVE each one and check all wiring
to see what's going on. You may discover a mistake in the process of
taking one out that is causing the trouble. 

When you restore normal operation, you will know that the last thing you
removed is the problem. Now go back and carefully study it to see what
was wrong.  

That's not an easy approach. It's just the reverse approach to what I
normally recommend (making one change at a time and making sure the rig
works properly before going on).  I'm cc-ing the reflector in case
someone else has a better idea!

The problem is that sometimes something like this happens that has
NOTHING to do with the change you made even though you may have caused
it in the process. It might have been something you did quite
accidentally while handling the rig. If you discover the problem very
quickly after doing the work, you will often remember touching something
or at least remember exactly what you did and can often find a broken
lead, bent pin, mis-mated connector, etc., that you accidentally let
slip by. At this point it's almost a "ground up" troubleshooting
exercise. So be vigilant when looking at the rig for anything at all
that seems out of place or that you may remember seemed odd when you
were working on it.

Ron AC7AC
K2 # 1289

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