Not quite. They can calibrate the couplers all they like. Unless
the directivity is high the readings are erroneous in the real
world. The claimed directivity of their V/UHF couplers is awful
and the data sheet contains a load of nonsense trying to explain
why readings vary with cable length. The HF couplers are a bit
better, but far from delivering the sort of accuracy they imply.
From memory, HP436A measured with an accuracy of around 3%. The
fourth digit in power reading in their prime photo is meaningless,
the third isn't much better than 0 or 5.
Steve
> "The cable and attenuator errors can be known without error, all he has to
> do is pay a
> cal laboratory to characterize each at the test frequencies."
>
> I've watched the Array Solutions guys calibrate their PowerMaster couplers.
> They use their VNA2180 to accurately measure their cables and attenuators.
> So the only inaccuracy is the tolerance of the HP power meter.
>
> Phil - AD5X
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