[Yaesu] RF Metering

Dr. Gerald N. Johnson geraldj at weather.net
Wed Jun 1 13:16:51 EDT 2011


HP/Agilent 436 family of RF milliwattmeters use thermocouples up through 
millimeter wavelengths. The key may be using fixed resistors for the 
loads and the thermocouples only to sense temperature rise of the load 
resistors. Unfortnately the power range is limited to less than a watt 
in most cases and the sensor prices begin at more than a kilobuck each 
with a similar price for the meter.

73, Jerry, K0CQ

On 6/1/2011 11:45 AM, Bob wrote:
> Thermocouples in RF meters are a very POOR choice for measuring SSB
> voice signals, due to the slow response! A Bird 43P is MUCH better for
> SSB peak power, the thermocouple is OK for CW of FM type, AVERAGE power
> readings, but finding a thermocouple with low enough inductance for
> UHF/ MICROWAVE accuracy is likely to be a problem.--73, KC3VO, Bob Curry
>
>
>


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