Steve,
Set the menu ATU parameter to CAL P when adjusting R1 for the power
reading. CAL S is the setting used to align the SWR (use a dummy load
which will provide a known SWR such as a 25 ohm or 100 ohm load which
give a 2.0 SWR).
Also, be certain that your RF Probe is a type that provides RMS
readings. Some (those with the diode connected in series with the meter
probe) will indicate peak voltage. At 5 watts, 15.8 volts is the
correct voltage for an RMS reading probe across a 50 ohm load, but if
your probe indicates peak voltage, you must adjust for 22.36 volts minus
the diode voltage drop. If you are looking at an oscilloscope, you will
see a peak to peak voltage and that should be 44.72 volts for 5 watts.
Consider how you checked your dummy load? If you checked it with an
ohmmeter, that is the value at DC, but the value at any given frequency
may be different - check it with an antenna analyzer to be certain.
73,
Don W3FPR
list1 wrote:
Hi all,
I decided to realign my ole trusty KAT2.
Adjusting the bridge null seemed to go OK. However, when I adjust the power
knob to give 15.8 Volts (5 Watts) at my precision dummy load (50.3 Ohms),
turning R1 clockwise to the maximum position only shows 4.4 Watts on the CAL S
readout.
Any suggestions?
_______________________________________________
Elecraft mailing list
Post to: Elecraft@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
