[Elecraft] KPA100 Upgrade and KAT100 Problem

[Don Wilhelm]

John,

I believe the problem is entirely in your KAT100.

Check all your connecting cables first thing (do a continuity test on both
the center conductor and shield and check for shorts).  It sounds like your
tuner is operating into an open circuit or a shorted one.

If you have an antenna analyzer, check each cable with it while connected at
the far end to a dummy load.

After checking the cables, if you still have problems, try re-calibrating
the wattmeter in the KAT100.  Also check the soldering in the KAT100 control
and wattmeter sections - particularly RP1 and the pins of U3.  In fact check
all the soldering in the KAT100.

Pins 6 and 7 of U3 must go to a low level (to scale the wattmeter readings)
when high power is active.  Check to be certain that is happening and that
the low level scaling signals are getting to pins 2 and 4 of RP1.

73,
Don W3FPR

> -----Original Message-----
>
>
> I had been having problems with my KAT100 and hoped the KPA100 upgrade
> would help.  I installed the upgrade and all works well with an external
> tuner other than the KAT100.  But, the KAT100 problems persist.
>
> Here's the problem.  The KAT100 tunes fine on all bands into my 50 ohm
> dummy load if I set the power to 10 watts.  But, if I set it to 11
> watts, engaging the KPA100 build into my K2, the bands 160m through 40m
> won't tune correctly.
>
>