Re: [Elecraft] K2 PA repair kit

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Re: [Elecraft] K2 PA repair kit

n0jrn
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?

Jerry

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Re: [Elecraft] K2 PA repair kit

Don Wilhelm-4
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?
>  
>
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Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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Please help support this email list: http://www.qsl.net/donate.html