> 3. The 160/10 seems a bit short for efficiency on 160m. I make the
> impedance of the driven element about 2.6 - j 764 at 1.8 MHz. Ground and
> tuner losses will nail you badly.
I would second this, and you should probably consider building a
low-loss, high Q loading and matching network for 160 and (possibly)
80.
A tapped-coil matching network with a large inductor wound in air or
on a low loss form would do a much better job on 160 than an
autotuner. I use an unloaded 12m vertical (Spiderbeam telescoping
fiberglass pole + a wire) on 80, 40 and 30m, and will soon add 160, so
I can let you know what I come up with for a matching coil. I don't
expect much efficiency from it, because my ground radial field is not
so great, but it'll be better than NO antenna.
Wow, though... I just looked at the price of the titanex GP 160/10...
I find 600 Euros? Something to consider is that using the fiberglass
pole + wire like I've done would give you basically the same antenna
with lots and lots of Euros left to spend on the matching networks and
other contesting gear. I think the fiberglass pole is Eur 89 or so.
For Eur 200 you can get an 18m fiberglass pole which would do better
on 160 and 80.
I guess the longevity of a heavy aluminum vertical might be more than
the fiberglass poles, but I suppose that depends on the particulars of
location and weather. fiberglass + wire is going to explode in a
lightning strike, I expect, but would do better in salt air than
aluminum. A wire vertical will also have a faster reactance change
than a 50mm base diameter aluminum vertical, and therefore, I guess it
has less useable bandwidth. There are things to consider other than
price if you're going to go this route, but if you're really looking
for "cheap and cheerful, " though, I can recommend Spiderbeam's stuff.
I'd expect my 12m pole to take quite a wind and still stand back up
straight afterward.
Dan
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