[Elecraft] too much output power

[James T. "Jim" Rogers]

Ken wrote:
        I am on the alignment and test part 3 of my K2, and am having a
problem with to much output
power, seems output power is wide open, Hi cur comes on in the LCD, and F1
finally kicks it off, and it
makes no difference as to where the power level knob is turned, all the way
off, or all the way on, is still
wide open, all bands, seems to receive just fine, all bands, there has been
no smoke, and nothing is
getting hot, cept F1,  any suggestions ???

Ken, I will share information Don Wilhelm shared with me and it helped me
understand what was going on. The POWER control is "requested power". That
is one parameter to the MCU which is acting as a comparator. The other side
of the equation comes from the rf detector VRFDET(RF Board Sht 3 of 4). The
MCU will crank up the drive via the BFO Buffer/Attenuator(RF Board sht 2 of
4) circuitry until VRDET compared with POWER satisfies the comparison
equation.

1)I would first make sure the RF Detector is functional. Don't forget all of
this has to pass through all those connectors to get to the control board.
2)I would then check the BFO Buffer/Attenuator. With all that power VALC
should be trying to shut that down.
3)I would then check the origination of VALC,(control board) which actually
originates from the POWER you have dialed in via the MCU reading VPOTS and
passing the information on to the DAC (u8 on the control board) which
generates a analog voltage, VPWR to the VALC circuit (U10a and Q8 on the
control board). U10a is a smoothing filter to take out the noise as you
change the setting of POWER.

I hope this helps.

73 Jim W4ATK
K2 #4028