[Elecraft] K2/100 comment

[David B. Perrin]

Hi-
 I built K2 number 1871 a year ago last February. It worked the first
time and it has worked flawlessly since. At Dayton, I had to have the
amp. I had problems as well, and I am quite confident they are now
cured. Thanks Elecraft and Gary!
 The problem, I believe (for me) was that since I had no reason to be
inside the K2 for 18 months, I forgot the complexities of installing
the heat sink on the bottom of the K2. My K2 finals blew during the
first extended transmission while using the amp. 
 The cause, I think, was that I had nearly shorted them to ground
during re-assembly, and a little heat from the transistors while
transmitting did the rest. The bushings are particularly delicate and
easily can move during assembly causing-almost a short to ground.
 The final transistor screws, insulator bushings, thermal insulation
pads and their mounting instructions need to be reviewed in the K2
manual! It was easy just to whip off the K2 bottom cover/heat sink
when told in order to do the necessary board modifications but... in
re-assembly...

go back to the K2 instruction manual and be certain to follow the
assembly instructions!! Pages 69 and 70.

 High temperature silver solder (from radio Shack)was used in my
original construction. It was widely touted, on the reflector,  as the
thing to use when I built my K2. It is a bear to wick out when
desoldering, it does not come out easily. If you need to replace
components more than once, I suggest you Ohm out the traces on both
sides of the board to insure you do have continuity from a component
lead itself to the next component.

Just my two sense (sp) worth. Thanks for the bandwidth.

73 de dave K1OPQ