I may try this approach, my tower is only 50' or so but It has guys on it,
The guy that goes out to my back yard is about 75' or so but is also
connected to the chain link fence that winds all thru the block that I live
on. (not sure what effect the fence will have if any)
Just a note: the guys do little more than keep the tower from swaying (rhon
25) when I am working on antennas etc.
I have radials everywhere and ground rods and there tied into the chain
link fence ( I lost count of how many)
After I get it up, I can connect my antenna analyzer and see what kind of
readings I get.
When I make the feed point connection I can make it in a way that I could
remove the shield from the tower and change it into a normal dipole. I am
not sure where I could run that end but maybe I can sweet talk a neibor..

Am I NuTz?

I love playing with antennas...

Joe
"Cecil Moore" wrote in message
. ..
HS wrote:
One easy thing that you might try, is to slope a 1/4-wave wire from the
top of your tower, connecting your coax to the wire, and coax shield to
the tower at the feedpoint, this way your tower will be the "other leg"
of the dipiole, or a "counterpoise". Then just trim the 1/4-wave wire
for swr.

The ARRL Antenna Book says that works if the tower is 1/4WL
tall or taller. A 1/4WL tower on 160m would be about 130 feet
tall. If the tower is less than 1/4WL tall, it seems to become
the major radiating portion of the antenna. I just modeled a
33 foot tower and a 100 foot wire on 1.9 MHz. That total length
is just about 1/4WL and winds up looking something like a gamma
fed inverted-L. The feedpoint impedance at the top of the tower
is low at ~8 ohms.

Such an antenna has a 50 ohm feedpoint impedance somewhere
along that horizontal wire. In my 33'-101' version above, the
50 ohm feedpoint is about 40' from the open end of the 100' wire.
And, of course, the feedpoint currents are unbalanced.

100' total
+-----------------------FP---------------
| 60' 50 ohm 40'
|
|33' tower
|
|
+-----GND
--
73, Cecil, http://www.qsl.net/w5dxp