OK, an idle thought crossed my mind as I was working on the front porch tonight, and I wanted to run it by the antenna gurus out here.
As you may recall from an earlier thread, I am going to be putting up a flag pole vertical sometime this summer, as part of the front porch remodeling project. And it's not a question of "if" but "when" -- the fiberglass flagpole is sitting in the house waiting for the right point in time in the project.
Since it's a fiberglass pole, obviously I'm going to be running a wire up inside it, approx. 21 - 22 feet; the length of the pole is 22 feet, I'm not sure if I'm going to run the feed out above or through the mounting post yet. And it's going to connect to an SGC tuner mounted right at the base, so loading should be relatively easy (famous last words).
Now, the idle thought is simply this... why not run more than one wire inside? That is, run multiple lengths cut for each band (10, 12, 15, 17, 20 & 30 meters) alongside the "main run". This ought to make the flag pole resonant (more or less) on each band; or close enough that the tuner won't have to "work" too hard to match.
For this to work, it would have to be insulated wire. The main length would also be the vertical support. Of course, everything would be tied together at the main feed point. And it should go without saying that there will be a nice radial field laid out underneath the antenna (including underneath the deck that's going to go over the concrete porch) so that shouldn't be a factor.
The theory is that, as implied by Ohm's Law, energy should flow to the most resonant wire on a given band, as the path of least resistance. And I'm confident that this should work, recalling the mobile antenna setup I had on my old van -- 2 Ten-Tec mobile antennas (their short-lived clones of the hamsticks) on 40 & 15, plus a 10 meter whip (OK, a CB whip trimmed), all in parallel on one feed. Three bands, no switching, no tuning (which was nice considering that the TS-120S I ran mobile at the time didn't have a tuner built in!)
And I will try to borrow an antenna analyzer, trying to cut the wires as close to resonance as possible.
Thoughts?