[Elecraft] K2/100, KAT100 strange tuning problem

[Don Wilhelm]

Bob,

There is nothing unique to 40 meters in the KAT100, *but*.

Behavior like that *could* be related to a parasitic oscillation in the 
KPA100.  The parasitic usually revealed itself during a TUNE operation 
with the KAT100 also installed.

The KPA100 T/R switch was re-designed to address that very problem.  If 
your KPA100 was ordered before last December, it has the old T/R switch 
in it, and can have the parasitic problem on 40.

I suggest you promptly obtain the KPA100UPKT and install it in your KPA100.

73,
Don W3FPR

Solosko, Robert B (Bob) wrote:
> Hello All,
> 
> 	I hope that someone can suggest where to start tracing down a
> rather strange tuning problem that cropped up in the middle of working
> the IARU on Saturday. The short description is that the K2/100-KAT100
> stopped tuning in AUTO mode when in high power mode on 40 meters. Here's
> some of the details:
> 
> 1 - Tuning with the K2/100 and KAT100 on 40 meters has worked fine since
> I completed the KPA100 (rev. D) 6 months ago.
> 
> 2 - I had no problems tuning for about the first 10 QSOs on 40m, and
> then the rig suddenly wouldn't tune at all when in high power mode
> (there were no lightening strikes during that time) - then tuning became
> erratic.
> 
> 3 - Tuning worked fine when the power was reduced to low power mode: all
> I had to do was reduce the power just to the point where the power LEDs
> on the KAT100 switched from high power to low power and everything
> worked fine - then increasing the power just to the point where the
> power LEDs on the KAT1200 switched from low power to high power and the
> KAT100 wouldn't tune at all.
>