On Sun, 2 Jan 2005 16:03:08 -0500, "David J Windisch"
wrote:

Hi, all concerned:

www.g3ycc.karoo.net/lattin.html

is the corrected url.

If the dimensions are added up, the overall physical length approaches that
of an 80M dipole. "Loading-effect" of the "fat-wire" dipole could be helped
along if needed on 80M by additional wire length past A.

The A-stubs reduce the electrical lengths each side to overall
40M-dipole-size.

Ditto B-stubs on 20M.

Ditto C-stubs on 15M.

Changing the D-lengths to single wires, or shorting both inner ends,
completes the 10M-dipole section.

Editorial comments:

The feed shown is "incorrect". Stubs at D are not needed, unless one wishes
to add higher-frequency capability. Single wires are sufficient for the 10M
portions of the dipole.

This Lattin antenna is not easily constructed or tuned, and it reminds me of
something from the category of solutions running around looking for
problems.

The current amateur application that I can think of which is done "properly"
is the KLM h-f tribander. The stubs are of open-construction, and the first
stubs, at the outside end the 10M portions of the antenna elements, can be
seen easily, even in pictures.

Dear Dave,

I could certainly be wrong, but my calculations indicate that the "C"
stubs are designed to produce a trap for 10 meters - not 15 meters.

The feed shown is at worst ambiguous. Actually, according to my
measurements and according to common sense, the "D" stubs perform no
useful function. You can feed from either wire or you can twist those
two wires together and feed jointly - same result.

I think the purpose in carrying the same material all the way through
the design was the real point, but section D is just wire for the 10
meter dipole. There may have been some subtle reason for having a stub
at position D that resonates at 25 MHz, but I don't see it.


Bob, W9DMK, Dahlgren, VA
http://www.qsl.net/w9dmk