[Lowfer] TAG dies! :)

[John D]

>I can't seem to locate my Xerox copy of the Krauss chapter on loops but
will
>will keep looking The lobes shown in his figures were extensive (nice
>graphics, too) but it may be that the examples I remember were for loops
>of many WLs circumference.

I expect that's the case.  Up to at least a half wavelength circumference
(as in single-bay FM broadcast antennas), there are no funky lobes to
contend with at all.  It's a lovely doughnut shape, maximum radiation in the
plane of the radiating element, minima at right angles to the plane--just
like an electrically small loop.  However...

>I did manage to find a good article covering the radiation resistance
>for loops of all dimensions. Turns out the radiation resistance is still
>very small at 1/4WL. So does this say that most of your 53 ohms is
>ground loss and/or tree loss?

Rr may be very small, but is no longer miniscule.  And yet, the
environmental losses for a loop of this size increase too!

It's because there is now significant phase delay around the circumference,
which means that there are greater potential differences between different
points on the conductor.  The magnetic field no longer dominates the
near-field energy to the almost total extent it did with truly small loops.
There is also an electric field to contend with; not yet huge, as it will
become at one wavelength circumference, but one which can no longer be
ignored either.  It definitely will interact with antenna supporting
arborage, the earth, and most any other quasi-conductive objects in its
immediate vicinity.

Lots to experiment with there!

JD