[Elecraft] K2/10 problem

[W3FPR]

Allan,

The first thing to suspect is the wattmeter diodes in the KAT2 - I would 
arbitrarily replace them - they are 1N5711 type.  That should cure your 
power setting vs. actual power problem.
Set the 2 pots on the KAT2 as instructed in the manual after replacing 
the diodes.
In fact, remove the KAT2 until you get the rest of the K2 working, then 
check the power setting vs. the actual power output.  The wattmeter 
diodes may be at fault, but eliminate the KAT2 until after you have the 
base K2 working properly.

As for you other problem of RX not working, yes a BFO reading of All 
zeros says something is wrong with the BFO (or the probe) - fix that 
first before going onto the ATU/power output problems. It is possible 
that U11 or one of its components has failed. Again fix that first.  
Remove the KAT2 and work into a 50 ohm dummy load until that is resolved.

Check the K2 internal probe by trying it into TP1 or TP3 to make sure it 
is working.  If the probe has a fault, it may be leading you down the 
wrong path.  Remove the heatsink and check for a broken connection at 
either end of the capacitor.  It that is the case, you can use any 10pF 
capacitor - I use a disk ceramic with both leads spread out to make the 
connections.

73,
Don W3FPR

On 6/27/2023 5:59 PM, Allan Forster wrote:
> Hi,
> I found that the actual power out did not match my setting, eg. I set 10 watts but power meter reads 14 Watts.
> Simple to calibrate the auto ATU or so I thought. While adjusting the 2 pots on the ATU the rig suddenly powered down.  When I switched it back on the RX was not working, I followed the alignment procedure and it seems that the BFO is dead. Ie. In CAL FIL the BFO reading is all zeroes
> Any ideas?
>
> Regards
> Allan G4NNJ
>