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Old February 21st 07, 06:59 AM posted to rec.radio.amateur.antenna
Owen Duffy Owen Duffy is offline
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First recorded activity by RadioBanter: Dec 2006
Posts: 1,169
Default Field strength - S plane summation

Roy Lewallen wrote in
:

Maybe the lack of responses is because of the obscurity of the
"s-plane summation". I've never heard of it, and a web search brought
only one or two possible hits from publications I'd have to buy in
order to view. Any principle with that low a profile on the web is
pretty esoteric.

Roy Lewallen, W7EL


Roy, to kick it along a little...

The technique calls for making sets of measurements with the antenna in
three orthogonal orientations and summing the z, y and z plane values to
an "s plane" value to represent maximum field strength. I think the
summation that is typically used is the square root of the sum of the
squares.

The technique suits automated measurement where a series of perhaps
hundreds of measurements at different frequencies are made, the antenna
is manually changed, and the series repeated etc. Software is then used
to process the logged measurements.

Clearly there is an issue about the temporaral nature of separate
measurements in each plane at a given frequency.

I was interested in any standards or regulatory "procedures" that may
exist that describe / mandate such technique. Most procedures that I
have found just call for orienting the antenna for maximum response
rather than the x,z,z trick.

I would like to understand its application better to for a view about
the appropriateness to particular applications. I suspect its main value
is in automated EMC data capture.

I am still on the BPL measurement tram!

Owen