[Elecraft] KPA100 Power Output Problem

[Don Wilhelm]

John,

Your KPA100 is working as it should!
TUNE will transmit at 20 watts - it was designed that way.
If you want to use TUNE at the setting of the Power knob, press TUNE and
DISPLAY together, or press TUNE and rotate the POWER control to the setting
you want (you are already doing that).

You should see full power output by pressing the key.

73,
Don W3FPR


> -----Original Message-----
>
>
>    K2  #4842  has  been fb for over a year, and I've been working between
>    baby  diaper  changes to complete my KPA100.  Everything has proceeded
>    smoothly through the bias current adjust, but having problems with the
>    transmit  tests.   All proceeds okay to about 20 watts.  With K2 power
>    control  set  to  50W output,  I hit TUNE and power output reads 20-25
>    watts on  both  K2  and  external meter.  While TUNING, I increase the
>    power  control pot clockwise, and power quickly jumps up to the higher
>    (50W) output  level.  Toggle  TUNE  off  then back on again, and power
>    again  drops  to  20-25 watts until I tweak/increase the power control
>    pot and power out then jumps to a level >50W.  Toggle again, output is
>    back  to 20-25 watts out until I tweak/increase the power control pot,
>    and  power  then  again jumps  up  to  an  even higher  level.  Toggle
>    TUNE off again and back on, and power out is back to 20-25 watts until
>    I  move  the  power  control  pot,  etc. etc..  With the power control
>    pot full clockwise the unit is putting out a full ~110W.  I re-did R26
>    alignment and  all  seems okay.  Checked  the common reflector section
>    and  didn't  see  anything  similar to this, so I'm hoping to get some
>    investigation suggestions from any willing higher powers.
>
>    Thank you in advance.
>
>    John / K0YQ
>