[Elecraft] KX1 problem/question

[Ron D'Eau Claire]

Right you are about the wrong reference designator on page 55 of the KX1
manual, Weymouth!  That should be Q6 of course.

The metal tab on Q6 is tied to the collector circuit. That's why all the
concern about insulating it from the case. So it should show something
around 1000 ohms or so resistance between the tab and ground (one of the
metal stand-offs that mount the KX1 to the case, or the PCB around the hole
for a stand-off. If that's what you are seeing, it's probably okay.

I trust that you're measuring the resistance between B+ (at the toroids as
described in the manual) and ground. The screw that holds the assembly will
be grounded, of course. It goes straight into the threads on the grounded
metal standoff that holds the transistor at the right height. 

The most common reason for getting a short at Q6 is a tiny burr in the case
that sticks through the thermal pad and touches the tab on Q6. The screw,
and the post under Q6, are at ground potential. Even though the shoulder
washer doesn't come all the way through the tab on Q6, it does the job. All
it is there for is to be sure that Q6 doesn't rest against the grounded
metal standoff under it, and the shoulder only needs to keep the screw
centered so it doesn't touch the tab.

If the tab isn't showing 1000 ohm or so to ground, check for a short in the
B+ line to ground! If you have a short somewhere else, it'll show up as a
short between the  tab on the transistor and ground. 

Ron AC7AC

-----Original Message-----

I'm unable to get a resistance measurement above 0
(zero) Ohms when putting the flat-head screw through
the case into Q6 (power transistor) ... the KX1 assembly
manual says to "Check the hardware around Q3."  

First of all:

Shouldn't this be " ... around Q6." 

Second:

Can I make any DMM measurements on Q6 itself to verify
that it hasn't somehow gotten shorted internally? I mis-installed Q6 at
first, and have tried to "salvage" the chip while waiting for a replacement
from Elecraft ...

Thanks for any replies ...

72/3, Weymouth Walker ...
K8EAB