[Amps] Time for New Power Meter

[KA4INM]

   On 05/02/2015 12:46 PM, Bill Turner wrote:

> ------------ ORIGINAL MESSAGE ------------(may be snipped)

> On Sat, 02 May 2015 07:47:20 -0500, NI0K wrote:

>> Measuring RF power accurately is very difficult. Have you ever seen a
>> wattmeter that has been certified calibrated to any standard? No,
>> because it is impossible.

   Bird Electrical thru-line power meters had a + or - 5% accuracy but
if you sent the thru-line section and the slug in for re-calibration it 
would return with a guaranteed + or - 3% (traceable to NBS) accuracy.
With the certificate to prove it.

> REPLY:

> There is a way, but it is a bit of work. If you are really serious
> about it, you can measure the heat rise  in a dummy load using first
> RF and again using DC. Simply adjust the DC power to make the heat
> rise the same as the RF and there's your answer.

   This is exactly how the "HP Agilent 435B Microwave RF Microwatt Power 
Meters" work, the kind with the separate sensors heads.  And it's ilk.
-- 
   Ron  KA4INM - Youvan's corollary:
                 Every action results in unwanted side effects.