[Elecraft] Blown finals

[Don Wilhelm]

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.
>
>