[Elecraft] K2: KAT2 null adjustment

[Don Wilhelm]

Peter,

Yes, the KAT2 can be nulled without removing R6, and yes, obtaining a 
minimum reading of 10 or 11 is quite normal.

The reason for initially having R6 not installed has to do with checking 
for shorts - but since the manual calls for a specific voltage range for 
the check, the null procedure has to be completed first.  There is no 
need to remove R6 when rechecking the null.

If you have a good 50 ohm resistive dummy load and have an RF Probe, you 
can calibrate the forward power with those tools, and they will be more 
accurate than a run-of-the-mill wattmeter.  P=V^2/R - Power equals (RMS 
voltage squared) divided by the Resistance.  Several trials should 
result in a well calibrated wattmeter inside the KAT2.

73,
Don W3FPR

Peter Wollan wrote:
> According to the manual, it should be possible to adjust the null to
> 000, and it should be a broad null.  On mine, it was extremely sharp,
> and wouldn't get lower than 010, flickering to 011.  Does this indicate
> a problem?  I went ahead and finished the installation -- the voltages
> were fine, and the tuner seems to work just dandy.  
>
> I'm using a homemade dummy load, which seems to test out ok at least at
> the lower frequencies, and I don't have a calibrated wattmeter (yet,
> will borrow one soon).  
>
> Can/should the null be recalibrated, even though the resister has been
> installed?
>
> 	Peter N8MHD
>
> _______________________________________________
> Elecraft mailing list
> Post to: Elecraft at mailman.qth.net
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
>  http://mailman.qth.net/mailman/listinfo/elecraft    
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>
>
>