Is is valid to test a thermocouple-type RF Ammeter using low
frequency (say 60 Hz) current? I did so and got quite
reasonable results. Hey, current is current, right?

I have three different thermocouple-type RF Ammeters, with
FS ranges of 1.5, 2.0 and 3.0 RF Amps that I wanted to test.
The 2 Amp meter has an external thermocouple (16 mV DC for 2.0 RF Amps)
and the other two have internal thermocouples.

I hooked them all up in series, and also in series with a
Fluke digital AC Ammeter, fed them from 6.3 VAC through a suitable
dropping resistor. All readings agreed within a few percent at various
currents.

Can I now assume that these meters will also function correctly at RF
(i.e. 3 - 30 MHz)?

Thanks.

-Al, W2ADS