[Elecraft] KAT100 null

[Don Wilhelm]

Bill,

That indicates something is wrong.  Are you using a good dummy load with 
a very short connecting cable?  If you have any doubts about the dummy 
load, check it (and the cable too) with an antenna analyzer - anything 
other than a 50 ohm resistive load can cause problems with obtaining a 
good null.

The other thing that can cause difficulty with the null is any reactance 
in the tuner - there is a small amount of residual, but not enough to 
change the null drastically.  Look the tuner over carefully for 
unsoldered connections in the relays and inductor and capacitor parts of 
the tuner.

As for 'dumb' things, make certain the wire to the input jack goes 
through the center of the toroid.

73,
Don W3FPR

Bill Carpenter wrote:
> Everything has gone fine with my new KAT100 until I got to the SWR 
> bridge null adjustment.  The best null I can get is about 1.9 to 2.0 
> volts. I checked T1 and even took it out and rewound it with new wire. 
> The 4 leads of T1 are in the correct holes and continuity checks fine. 
> Everything else in the bridge circuit looks fine to me and the coax 
> jumpers I'm using are fine. I have the KPA100 so I'm attempting the 
> adjustment at 20 watts.  U5 is installed correctly.
>
> Very frustrating!  Any help is GREATLY appreciated!!
>
> 73,
>
> Bill NZ0T
>