[Elecraft] RF Probe measurments - K1

[Ron D' Eau Claire]

> I'm not at home right now, but the KAT manual said 14 volts.
> Hmmm - maybe a
> fudge factor needs to be added, but 1.8 volts ?!  Interesting when I made
> the adjustment, the max voltage of 19 volts did agree with the formula for
> 7.2 watts.  Go figure !
>
> Jamie
> WB4YDL


Whatever the manual says, YOUR calculation is right! 15.8 vrms across a 50
ohm load is, indeed, 5 watts (well, 4.99).

The Elecraft probe includes a scaling resistor that should give you a direct
readout in RMS provided that you use it in a voltmeter circuit with an 1l
megohm input resistance. The accuracy is dependent upon those resistances
both being close so the metering circuit reports 7.07% of the d-c voltage
across the diode in the probe.

Ron AC7AC
K2 # 1289