Re: Experimental Help - Terry?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>" <evp-at-pacbell-dot-net>

> I'd say that a thermal detector is THE way that RF power is measured
> (accurately)... Whether a bolometer or thermistor... The fancy detectors use
> balanced circuits that hold the detector at constant temperature with a DC
> current. The amount the DC current decreases (and the resistance..) tells
> you how much power is being dumped into with the RF.  Uncertainties in this
> sort of sensor are:
> 
> 1) How accurately you measure the DC current
> 2) How accurately you hold temperature (this one's easy, because it's
> basically a nulling to hold it at a zero, rather than actually measuring
> something...)
> 3) RF mismatch.. The RF power has to really get into the load, and not get
> reflected back.  The connectors are a problem here..
> 
> But, in any case, all those HP power meters use thermistor heads...

	How would you go about matching the HP 50 ohm thermistor head to the
output of the Tesla Coil, so that the correct power could be measured?

Ed