[Elecraft] K2 PA repair kit

[Don Wilhelm]

Jerry,

The K60XV should not reduce the base voltage at Q7 and Q8.  BUT, since 
it is, remove the K60XV, put a jumper wire from pin 3 to pin 5 on J13 
and stick the leads of a small value capacitor (4.7 pF is ideal) into 
pins 1 and 3 of J15.  The K2 should operate normally except for 60 
meters with that jumper/cap combination in place.

The 0.64 volts is within range, even though it is a bit on the high side 
of what I normally like to see.

As far as the K60XV problem, if your K2 has a serial number less than 
3000, while you have the heat-sink removed, check the cut that was made 
on the 8T voltage line to pin 6 of J13 (see the K60XV installation 
instructions).  If the cut was not complete it would interfere with the 
K2 power control as well as dragging the 8T voltage rail down.
If your K2 is later than SN 3000, look for a solder blob making a bridge 
to the 8T voltage rail near J13 pin 6.

73,
Don W3FPR


n0jrn wrote:
> Don:
>
> Should I have the K60XV plugged in while testing the base voltages at Q7 and 
> Q8 ??
>
> Maybe I should ask
>
> Should have the K60XV affect the base voltage of Q7 and Q8???
>
> I have .64 volts at the base of both transistors without the K60XV.   Plug 
> the K60XV in and it drops the voltage to .40 at both.
>
> I assume the added board should have no affect which means I will move on to 
> troubleshooting it after I get the K2 back together.
>
> Your opinion?
>   
>