[Elecraft] KAT100

[Don Wilhelm]

Raimon,

Re-adjust the null of the KAT100 wattmeter - it is almost, but not quite 
right.  After you re-do the null, you will have to go through the power 
calibration and SWR calibration again.

The reason that you see the SWR indication on low power and not on high 
power is because a scaling factor is used on high power and swamps out 
the small reflected voltage at high power, therefore the LED does not 
light.  As I said, the null adjustment is close to correct, but not as 
close as it should be - you may only have the 'touch the trimmer cap' 
slightly to make the difference.
Use a low scale on your DMM when observing the null point and rotate the 
capacitor through the area which shows the null to be certain you have 
it in the center of the null range.

73,
Don W3FPR

raimon wrote:
> I substituted D1 and D2, but the problem persists.
> Connected to a dummy load, and ATU menu to CAL, the LCD of the K2/100 
> shows the requested power and swr 1:1 (confirmed with an external 
> wattmeter and swr reader), with the difference that at low power the 
> first left LED of the ATU100 lights, and at high power none of the 
> LEDS light.
> Switching between CAL and AUTO you hear relays switching, as well as 
> when switching to L0-L8 etc.
> Where should I look to find the reason of this malfunction?
> Thanks and best regards
> 73
> EA3EZO
> Raimon
>