...3-section; extends from 8'4" to 23' 2";
The problem with an 9' minimum pole is that I can't reach the
top to extend the sections when the pole is vertical with the base
on the ground (unless I stand on a ladder). That means I have
to extend it horizontally, then tip it up into place, unless there
is something convenient to stand on.
That's why I would look in the window washing section of the
store and see what you can find with a minimum length of 6'
or so instead.
...Not yet sure whether to use coax or balanced ladder line. The run would be about 20' from the feed point to the outside wall of the shack where it would connect to RG8 and run another 15' to the rig.
I don't know that you will gain much if the ladder line is that short,
especially with a relatively long piece of coax on it. My preference
is to bring the ladder line all the way in to the tuner.
That's because the ladder line will transform the antenna impedance
(it won't match the impedance of the antenna on any band), then
the coax will transform it even more. With the wrong combination
of lengths, a 50 ohm antenna impedance can end up as around 1 or
2 ohms at the tuner, which isn't good for efficiency, even if the tuner
can manage to match it. The same antenna fed with ladder line the
whole way will be somewhere between 50 ohms and 4000 ohms -
still might be outside the matching range of your tuner with some
lengths, but it avoids the very low resistances.
And that evaluation needs to be done for each band as the electrical
lengths change with frequency.