[Elecraft] [K2] Erratic power control with base cw K2

[Don Wilhelm]

  Al,

Do you have the KAT2 installed? - you said a "base K2", but some use 
that term for any K2/10 without consideration for the options.

If you have the KAT2, disconnect it and run it into a good 50 ohm dummy 
load to see if the condition still exists.

If it works smoothly without the KAT2 and badly with the KAT2 installed, 
there is something erratic in the KAT2 wattmeter circuit - I would 
arbitrarily replace the wattmeter diodes.

Be aware that a bad cable between the K2 and the dummy load could cause 
that kind of erratic behavior.  The K2 must properly sense the actual 
output power and feed it back to the MCU so that a comparison with the 
requested power can be done.

It is also possible that something is awry in the firmware chip.  If you 
do not have success, the next thing to try is to write down all the menu 
settings (including your filter settings) and do a master reset (hold 
the 4, 5, and 6 buttons down while turning on the power).  Yes, you will 
have to reenter those menu settings, but it can straighten out problems 
that seem to exhibit erratic behavior.  Try removing and re-seating the 
MCU before attempting the master reset - any oxidation on the IC pins 
should be wiped clean by the re-seating process.

On 6/27/2011 12:09 PM, Alastair Couper wrote:
>
>> What I am suggesting is that there may be no problem at all - check 
>> with normal CW keying.
>>
>
> It's the same in cw as in tune. I can't reliably set the power at any 
> place but max. For sure, definitely not normal operation.
>