Curt,

Situation -- lack of proper power control - the K2 transmits a full 
power no mater what the power request knob is set to.

I suspect that you left the antenna connected to the K2/100 when not 
operating.  A static surge from the antenna (wind, rain, snow, lightning 
induced) caused the KPA100 diodes D16 and D17 to be damaged (I would 
check the wattmeter diodes on the KAT100 as well).  These diodes are 
right at the K2 antenna jack and are critical for the K2 to control its 
power level.

The best future cure for this problem is to disconnect the antennas from 
the K2 when not operating.  An antenna switch is preferred rather than 
physically disconnecting the coax.  PL-259 connectors mate the center 
conductor before the shield and if there is a charge on the antenna, 
that can damage the diodes when the antenna is connected - a simple 
antenna switch solves that problem.

Wind, rain, snow and nearby lightning can produce a significant amount 
of charge on the antenna.  A DC path between the coax center conductor 
and shield will do wonders to minimize that charge.  A high value 
resistor (5 k to 10k) or an RF Choke of 100 uHy value will provide an 
adequate DC path.  That resistor can be placed inside an antenna switch 
or can be installed directly at the KPA100 SO-239 jack with a TEE 
adapter.  Mount the choke or resistor into a PL-259 body and connect it 
to one side of the TEE adapter, the other side connects to the antenna.  
That will provide protection from normal antenna static buildup, but if 
there is evidence of nearby lightning, disconnecting the antennas is the 
only solution that will prevent damage.

73,
Don W3FPR

On 2/22/2011 8:51 PM, Curt Milton wrote:
> My K2 seems to be working fine -- the KAT100 is working, and it is 
> transmitting
> full power.  But there is no power indication on the LED meter, and instead I
> get a high current warning even though all is well.  This just turned up today
> on 'an old K2.'  It is misbehaving at all power levels - woops I just figured
> out the power control does not seem to be working when I am above 'QRP'
> settings.  The rig was only moved a few inches since it was last used.  Has
> anyone else experienced this ?
>
> 73 Curt
>
>
>
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