Jim, I would opt for the clamp on RF transformer...
Now, having said that, I recognize that anything we do to measure the RF
current is going to upset balance, impedance, etc. to a greater or lesser
degree..
I suspect the old RF meter ( I have a couple) is going to introduce enough
resistance in the element to upset the coupling between the elements... These
were originally intended to be used on open wire line at several hundred ohms
of Z...
With the clamp on RF transformer you can calibrate your RF voltage relative
reading by using a signal source and either RF voltmeter or oscilloscope, or
both, to give you voltage readings that can be mapped out as amperes...
But the issue is what do you expect to learn? I don't see the ratio of
voltage/currents without being able to measure vector/phase as being
informative... An example...
Two loaded short elements coupled to form a Yagi/Uda beam will have higher
currents in both elements than a full size, unloaded Y/U beam for a given
identical drive power...
A Y/U beam made of a folded dipole (300 ohm twinlead) driven element (or quagi)
and a shortened, loaded reflector will have significantly different circulating
voltage/currents between the DE/REF, yet still form a beam pattern...
This is a fascinating question that I don't have many answers for... Maybe
some of the gurus with electronic engineering background will discuss this...
I await with great interest...
denny / k8do
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