[Milsurplus] mf antennas etc.

[Rob Flory]

This will be a really fun way to put all those old Navy transmitters to
use.  I wonder what became of those TAJs in South Dakota or wherever they
were stranded.

It would take a lot of money to get antenna efficiencies into the tens of
percentage range.  With a 100-watt Navy transmitter, you won't have to.

Broadcast standard is 120 x 1/4 wave radials.  That is typically with
full-height or even extended vertical radiators.

To put a world class signal on 160 at WW2Y, Peter and I put down 40 quarter
wavelength radials on each of 4 vertical elements.  That was expensive in
copper, labor, acreage, sweat, and blood as there was a lot of multiflora
rose involved.  The magic tool was what we called the Bangalore Torpedo, a
ten-foot pole with a hook on the end that we used to push the wire under
rose bushes and other obstacles.  It also helped in maintaining a steady
heading.

Moving down in frequency by a factor of 4 the trees havent't gotten any
taller, so the antenna height is a smaller fraction of a wavelength, which
makes the radiation resistance very low.  The horizontal portion of a
"longwire" ends up being little more than top loading for the vertical
portion and may as well be eliminated by an inductor.  Making that top wire
a T instead of an inverted L makes the current in in non-radiating, which
means more signal goes to the horizon instead of warming the clouds.

The fellows across the pond are a bit head of us having gotten permission
to run serious MF several years ago.

I too, with an old-school mentality, prefer the idea of real-time ear copy
of CW to QRSS, though I would be interested in something intermediate.

My space at home grows ever more limited, so my activities will probably be
limited to ops from USS MASSACHUSETTS.

RF