[Elecraft] My K2/100 keeps resetting at high power

[Hisashi T Fujinaka]

After getting the suggestions from Eric and you, I looked at the
metering I have already.

I don't think it's the SWR bridge because the power reading matches the
wattmeter on my MFJ-1788. It steadily increases and looks about the same
as what the K2 shows.

However, the voltage/current meter I get to from the DISPLAY button is
odd. As I turn up the power before the KPA100 kicks in, I get an
increasing current up to 2.5. Then the current reading drops to 1.5 and
stays there. The metering of my power supply shows increasing current
and everything resets itself when it gets ~15-20A.

Time to look for the schematics, but any suggestions would be
appreciated.

On Mon, 2 Apr 2012, Don Wilhelm wrote:

> Hisashi,
>
> If by "reset" you mean the power turns off, you are most likely seeing the 
> internal resettable fuse trip.
> Normally you would see a HiCur message too.
> Usual causes for that behavior are either that the KPA100 wattmeter diodes 
> have been damaged or you have a damaged PA transistor in the base K2.
>
> Check the actual output power --
> Connect an external wattmeter between the KPA100 and a dummy load then set 
> the K2 power knob to about 30 watts.  set to CW and hold the key down long 
> enough to read the external wattmeter.  If it shows full power output 
> (greater than 100 watts), you have a problem with the wattmeter in the KPA100 
> - most likely bad diodes at D16 and D17.
>
> 73,
> Don W3FPR
>
>
> On 4/2/2012 11:37 AM, Hisashi T Fujinaka wrote:
>> OK, it's S/N 4355 with all the latest mods and it used to just reset
>> when I got on 15M phone. Now it's resetting on 30M CW while I'm trying
>> to work DX so it's bugging me. :)
>> 
>> Besides the standard checking for 10-year-old cold solder joints, is
>> there anything else to check right away?
>> 
>

-- 
Hisashi T Fujinaka - htodd at twofifty.com
BSEE(6/86) + BSChem(3/95) + BAEnglish(8/95) + MSCS(8/03) + $2.50 = latte