John Smith wrote:
J. Mc Laughlin wrote:

...
To use this technique at, say, 10 MHz with a yagi would be improbable,
but not impossible.

73, Mac N8TT


It would be interesting to hear ideas of those on "probes", methods,
etc., on how to do such, would be attempted--implemented-imployed ...
never say never.


The challenge is that one needs a probe that measures 3 axis E and H.
There are some clever designs out there based on a sphere with 6 half
loops sticking out. They've been used to make near field measurements
of broadcast stations, among other things. See, for instance, Gassman
and Furrer, 1993. Silva, et al., published an interesting fiber optic
probe scheme in 97. Driver and Kanda published a optically linked
sensor for making Poynting vector measurements in the near field in 1988
(IEEE Trans EMC). In the microwave area, the probe is usually an open
ended section of waveguide.

There are some clever techniques (see, for instance, the work of
Bolomey) where you put an array of small (non resonant) dipoles with
switches in the near field, and turn them on and off. You look at the
antenna's feedpoint impedance and from that, you can tell what part of
the field is affected by that dipole.

Once you've got your near field data, you need to post process. A
gentleman, A.C. Newell, literally wrote the book(s) on this technique at
NIST/NBS.






I think it would be interesting to hear on endeavors along these lines,
brave hearted individuals may be willing to share their experiences,
findings, guesses, etc. ... the bark is often much more dangerous
sounding than the the "bite." :-)

Frankly, "re-inventing the wheel" is welcomed here!

Regards,
JS