[Lowfer] Ultimate LOWFER Transmitter?

[Steve Olney]

G'day John,
>
> A better way to think about it is to split the power from one source into
> multiple parts and apply each feed to a separate antenna.  If the losses
> associated with each antenna are very high compared to the theoretical
> ideal, and if the induction zones around each don't couple very tightly,
the
> efficiency of the whole system *is higher than* that of the individual
> radiators, by a factor of 3 db for each doubling of the number of
radiators.
> This is the principle behind multiple tuned vertical radiator systems of
the
> type used at VLF stations such as SAQ, for example.
>

I am not sure if I am being subject to a gigantic leg-pull but here goes.

So you are saying that if I start with a typical LF antenna with say 1%
efficiency and feed it with say 1 watt (10mW radiated).    Using an
isotropic model for simplicity, this produces an energy density such that
the integration of the energy flow over the sphere = 10mJ/sec.   I then take
an identical antenna (which is *independant* as described previously) and
feed it with 1 watt synchronously , magically, it, and the first antennas'
efficiency jumps to 2% and the energy flow is now, once again magically,
40mJ/sec ?   Just how this works I would very interested to know.

I understood the gains made by multiple tuned radiators in VLF antennas has
more to do with a transformation effect of radiation resistance (and
losses) - something which does not happen with Stewart's *independant*
configuration.   Even in this case (SAQ) I would be interested to see
references which shows that the gains in efficiency result in a 3dB increase
for each doubling of the number of radiators.   I had thought that using
multiple radiators would go a long way to make it easier engineering-wise by
reducing the huge current densities associated with the mega-power of VLF
transmitters.

I would be interested in a rigorous explanation (no resistors and batteries
please :-) which further details the claimed doubling of efficiency for
doubling of independant radiators.    Of course we are not talking about
arrays of such a size as to have a directional effect.

73s Steve Olney VK2ZTO