[Elecraft] Re: KAT2: functional without proper power/SWRcalibration?

[W3FPR - Don Wilhelm]

Andrew,

The KAT2 does use the SWR readings for determining the best match, and it
uses the power calibration to determine the power output. So, yes it should
be calibrated.  The K2 will function, but the power output may be very
incorrect and the antenna match obtained will not be correct.

You can build an RF Probe easily from a diode (preferably germanium - like a
1N34A), a capacitor and a resistor.  If you keep the frequency to 40 meters
and below (which is perfectly adequate for the purpose), it will be
sufficiently accurate by just connecting your DMM probe to the resistor end
and ground - no need for the RG174 coax leads.  There is a schematic in the
back of the K2 manual that will tell you how to connect the 3 parts.  Use a
short ground and connect it directly across your 50 ohm dummy load.

You WILL have to have a good 50 ohm dummy load to do this accurately, but
the dummy load can be easily checked with an antenna analyzer, or even a
simple 50 ohm SWR meter.

73,
Don W3FPR


> -----Original Message-----
>
>
> I just finished building the KAT2 internal auto antenna tuner for my K2.
> I don't yet have access to an external wattmeter, or RF probe, so I'm
> wondering: are the last couple alignment / calibration steps necessary
> for operation of the KAT2, or will the KAT2 still reach a proper match
> even if SWR and power "calibration" has not been performed per the last
> bit of the manual?  May I use the KAT2 for now and simply ignore the
> possibly erroneous readings, or does the KAT2 actually rely on them for
> finding a match?
>
> Thanks,
> --Andrew, NV1B
>
>