On Sat, 3 Jan 2004 18:06:34 -0700, "Ken Bessler"
wrote:


After thinking a bit I'm leaning on the idea of just putting up a
10' mast and using it to support a Van Gordon all bander. My
building is 54x40 and 25' tall so by my math the 135 foot all
bander would overhang on the ground just a bit. There are trees
on the corners of the building so that's where the ends of the
antenna would go.

My current antenna would stay for comparison reasons.

Now - on my 153'2" dipole, I feed it with 12' of rg58 and a
9 turn, 2-5/8" dia coax loop at the feedpoint. Should I
duplicate this feedpoint for the 450 ohm ladder line of the
Van Gordon antenna or should I buy a balun? And if I buy
a balun, what ratio?

Hi Ken,

I don't see much advantage of one over the other, much less getting
into the benefits of BalUns and ladder line.

Any particular ratio only works if you actually observe that ratio
between line and load or source. This is unlikely if you are using
the antenna as an all bander (a distinction that is suspect in spite
of testimonials). A true all bander comes with issues, and knowing
those issues and responding to them allows all band operation.
However, you can achieve that status with a simple hank of wire, less
the appelation. In other words, you already have an all bander in
your dipole. It couldn't possibly work worse (or better) than the Van
Gordon except through choice of placement. In that regard, higher is
better, and it would seem you have plenty of length already.

IF it doesn't work (because it is whole wave on one band or the other)
you simply pair up a second in parallel (literally at the feed point)
and move on. The sad fact of it is, once you have a decent dipole up
(yours comes close enough), you have to invest many, many more dollars
and step up to a tower and beam to get to the next tier of
performance. Let's face it, few if any have towers supporting 80M
beams (and not many more with full-sized 40M beams).

On the other hand, 12 feet away from the feed point is awfully close.
This means you are literally part of the loss of the system (like a
hamster in a microwave). On the plus side, any high SWR would hardly
offer much loss over such a small run. However, such proximity often
leads to Common Mode issues (does your system refuse to tune some
bands? Even to folding back power?).

73's
Richard Clark, KB7QHC