Jack,
Forget about the current limited power source, there is another way.
Since your new finals are obviously blown, remove them and then power on
the K2 and do a TUNE while monitoring the voltage at the solder pads for
Q7 or Q8.
If the voltage is not in the range of 0.62 to 0.64 volts, replace Q11
and Q13 and then remeasure. If the voltage is still not within that
range, look for other problems in the PA transistor bias circuit.
Only after the bias voltage is correct, install the new PA transistors.
The K2PAKIT contains replacement transistors for Q11 and Q13. I
recommend that you use the K2PAKIT for replacement of the PA transistors
because the PA transistors are matched - if you obtained the
replacements from another source, they may have not been matched.
BTW - the "C" markings on the PA transistor solder pads are for the
Collector (Cathode has no meaning for transistors, only diodes).
73,
Don W3FPR
On 5/26/2015 9:19 AM, artus wrote:
Thanks Jack,
That sounds like a very reasonable starting point. We'll first check to see
it the finals are indeed blown; because my friend had a current limited
supply set at 1 amp, perhaps not.
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]
