In article t3ali.3392$Y_3.570@trnddc04, Woody wrote:

Well.. a million thanks for that. Quite a cool history lesson as well. So
now I'm looking for an SEA tuner... LOL...

Listen, that all makes perfect sense but just to clarify, a.) now I know why
that triton did so poorly when tested. We calc'd 1/2 wavelength for the
longwire, and b.) Again, for continuity and clarity of this thread for
future surfers...... what then, considering our discussed auto-tuners, would
be the optimal length for a longwire that would be used for amateur/MARS,
3-30MHz?
Pick 1/2wavelength on say 2.8Mhz and just cut it? Or calc 1/2wavelength on
the lowest and add 5% or some arbitrary odd number??
Which plan will offer the least chance of dropping a 1/2wl further up the
band on a desired frequency?

I think you'll need to run a a simple calculation, based on the
frequencies you actually want to use.

What you'll want, is a wire whose length is not particularly close to
any multiple of 1/2 wavelength, on any frequency you want to use. A
wire which would match easily on 80 meters (e.g. 1/4 wavelength long)
would be a bad choice if you want to work on 40 meters as well, as
it'd be 1/2 wavelength long.

A simple program or spreadsheet ought to be able to do the necessary
calculations... try every wire length from 66 feet to 132 feet and see
if you can find a length which is a comfortable percentage away from
an even multiple of 1/2 wavelength on each frequency. Or,
alternatively, iterate through each frequency, calculate the
1/2-wavelength multiples, and "blacklist" every possible length which
is too close to these multiples.

For what it's worth, SGC sells a longwire antenna 60' in length, which
they say works well on both lower and higher HF bands. It might or
might not be a good choice for MARS frequencies.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
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