[Elecraft] Re: KPA 100 pA issues,,,, puzzle...

[Don Wilhelm]

Bill,

Those symptoms sound familiar.  I believe your KPA100 is oscillating at 
about 600 kHz.

During the KPA100UPKT installation, did you change C31?  There is an 
omission in the kit contents and the instructions right now which is 
trying to be corrected, but has not yet been completed.

If you did not change C31 to a 0.22 uf capacitor, send a note to 
parts at elecraft.com and ask for one - the part number is E530295.

Installation of the larger value for C31 will stop an oscillation at 
about 600 kHz (what frequency does the LP100 say is being transmitted).  
Note for others following this thread - the C31 change is *only* to be 
installed if the KPA100UPKT has been installed.

73,
Don W3FPR

Bill NY9H wrote:
> initial symptom was the autotuner would lock up/ & reset the radio  
> when tuning ...only on 40 , so I ordered the PA upgrade kit...
>
> when running the k2 @ qrp .. the swr reads correct and the PA is 
> basically out of the circuit,.,,,,"1.3"  ....  this is on 40. both on 
> the set AND THE LP-100
>
> now my LP100 is giving me a big clue what is going bad in my K2/100 
> PA.....
> The problem is that I still don't understand enough of the basics../..
> but when i dial up over 15 watts  the swr reads 9.98  !!!  but when i 
> go back to under 15 watts .... the swr reads correctly...(LP-100)
>
> I know something is wacky in the kpa100....  and i thought it was in 
> the tuner...
>
> I have just completed the last of the upgrades to the KPA , but it 
> appears to not have helped...
>
> oN TYHE k2/100 the swr seems to read double when on the  PA  vs the 
> qrp,....on the other bands , but 40 has bigger /*issues...such as 
> locking up the autotuner... .which was the original sympton...
>