On Mon, 11 Dec 2006 20:04:23 -0500, "Jimmie D"
wrote:

I am considering using a crankup antenna as a1/4 wl antenna on 75/80m and
was wondering if ther is any history of someone doing this and using the
crankup feature for tuning the antenna. My guess is that it would be too
difficult to maintain electrical contact between the movable and stationary
pieces to be able to do this but still I am interested if anyone has
successfully pulled this off and how they did it.

Jimmie

I have a tubular crank up as you describe. I have never even attempted
to use the tower as a radiator because of the number of for seeable
problems. Since it is grounded, a shunt feed of some sort would be
required. It seems that anything that changes on the tower requires a
corresponding adjustment in the feed.

The raising scheme in my tower presents an unpredictable electrical
bond in the structure. I don't think minute to minute conditions are
predictable.

I considered a steel tape measure alongside the tower as a radiator,
but the model of a grounded structure did look promising!

A remote antenna tuner might show some promise but I will shy away
from it for fear of damaging the electronics with a rapidly changing
load.

As long as there is a need to raise & lower the mast anything
(dipoles, inv v, etc) are messy when lowered.

I consider it essential to be able to retract my tubular mast with a
Cushcraft A# on it!

John Ferrell W8CCW