[Elecraft] KX-1 power output varies

[Don Wilhelm]

Barry,

The losses through a properly assembled tuner are small.  I suggest you 
check the power output into a dummy load - I would believe there is a 
problem if the power is less than 3 watts with a 13.8 volt power 
supply.  Check first with the ATU menu parameter set to CAL, and then 
again with the ATU menu set to "tun" - you should obtain close to the 
same power.

If you still suspect the KXAT1, remove it and put the jumper on J7 
(between pins 1 and 3) and measure the power with an external wattmeter.

Be aware that the KAT1 wattmeter power indication is not always "right 
on" (it is not a precision wattmeter, but indicates "in the ballpark"), 
it will vary in the indication - you should assume that the actual power 
is somewhere between the two values it indicates.
The variation in the readings is typically about 0.3 watts - the range 
you are seeing is greater than normal, so be certain your antenna 
connections are solid and your coax is good.  If you are using UHF 
connectors in your feedline, make certain they are seated properly and 
tight.  UHF connectors depend on tightness for good conductivity.  Use a 
tool and tighten just a shade more than finger tight.

73,
Don W3FPR

On 8/24/2012 8:01 AM, Barry N1EU wrote:
> I've been using a KX-1 with KXAT1 ATU and random wire on 20M.  At various
> times I notice anywhere from about 1.9 to 3 watts power output.  In all
> cases, the ATU has indicated a low SWR after tuning.  I'm wondering why the
> power output varies so much.  Is this due to varying losses in the tuner as
> the match varies at different locations?
>
>