[Elecraft] K2 power amps Q7,Q8

[Don Wilhelm]

Leo,

I don't believe there is anything to repair.  Re-read the instructions 
carefully again - yes, you are to check for a short to ground - *BUT* if 
you find the resistance is zero, then you have a problem that must be 
corrected.

The resistance to ground from the Q7 and Q8 collectors normally starts 
out at 1.5k to 2.5k and climbs as the electrolytic capacitors on the 12 
volt DC line charge up - just how high it goes and how fast it gets 
there depends on your DMM - your reading of 3.6k is good, so put it all 
back together, checking again after you put the heat sink in place.  
Remember a low resistance to ground is a bad thing.

73,
Don W3FPR

On 1/30/2012 1:10 PM, leo wrote:
> My K2 serial number#7144 is almost completed. All tests have been good except
> the last resistance check on page 76.
>   Collector to ground should read 0 ohm,s .Even without the heat sink on I
> get 3.6K.Looking through the   E mail's that are posted I have removed
> transformer T3,recheched the collectors of Q7 and Q8,I get a reading of 0
> ohm's all good.I removed Q7 and Q8 so I can get a beter look at what is
> going on .the collector pads to ground without T3 are good,but when I short
> out pads A and B for T3 where the windings will go I get  reading of 3.6K.
>   Eye balling the board for shorts,I can't find a thing wrong and T4 windings
> look good to me.
>   Any ideas before I pack this thing up and send it off for repair.
>                                Leo KG6WNI
>