On Jul 4, 5:56 pm, wrote:


Is a shunt feed tower lossy??? poor radiator??? comments???

I am a Ham op WA4SZE : by the way, we will QSL the beacon when we
get it commissioned.

Thanks!!

The tower would not be the most efficient thing, being a 1/4 wave at
that
freq is about 442 ft. The four 10 ft radials, which I assume are a top
hat,
will be fairly useless at that freq. Too short to really do any good.
How long is the top horizontal wire is the "T" they are using at the
other
airport? I bet it's pretty long across.
What I would do if possible, is lengthen the top hat wires to be as
long
as you can. There does not really have to be four.. Two is enough, as
you can see from the other station. I don't know what the current
distribution
is with that setup, but it would seem that max current is at your
matching
device. The longer you can make that tower look electrically, the
better.
I'm not sure what the norm is for the usual NDB antenna systems..
I would basically use the same measures I would running a short mobile
whip.. Longer top hat wires would greatly help current distribution if
they
are long enough. To resonate the tower at that freq with no coil
loading, you would need wires about 315 ft... :/
But you could use shorter, and compromise a bit.
The ground is pretty important, but I think the current distribution
across
the tower equally so. I think all your current is huddled up around
your
matching device, and ground area.. Not really where you want it.
MK