"Telamon" wrote in message
...
In article ,
"Brenda Ann" wrote:

"Telamon" wrote in message
...

I would say bandwidth. Large aspect ratio antenna elements have a
narrow
band of resonance. It seems to me that there are some companies out
there that have tower kits that run 3 to 4 wires on spreaders so the
electrical diameter of the tower is increased. This will allow the
tower
to have lower VSWR over the +/-15KHz required.

I've been in on installing one of those kits.. lot of fun when you have
the
backup tower for the station only a few dozens of yards away.. you don't
want to forget to connect that ground in at least two places on the way
down
the tower..

That's great. Tell us how it works out when you tune it up.

In about 1989, we put a unipole on WDSR 1340 in Lake City, FL. The tower was
actually over 90 degrees, but the base was nearly 100 feet offshore in the
lake (thus the city name). The brackish water had pretty much dissolved the
ground system after some 40 years, and we put down a large ground mesh in
the water around the tower, and put a unipole on. The folks form Tennessee
came down, and they supervised the rigger. they strapped the tower base
plate to ground with three 2" copper straps, and use experience, the known
impedance of the tower and the rigger to find a connect point. They were
close enough that only two minor moves of less than a meter fund the right
match, and the station was back on the air.

The unipole did increase coverage, in an area where ground conductivity is
horrible. We did not notice any audio change, good or bad. The only long
term bad thing is that the outriggers had to be retensioned a bit, and in
major storms flying objects could break the wires or dislodge the fiberglass
yardarms that held them away from the tower, and on one occasion breaking
the critters off at the tower mount. I would not want one in a hurricane
prone region, as it would fly off the tower at the first impact of airborne
aluminum siding or trash cans.

In article ,
"David Eduardo" wrote:

"Telamon" wrote in message
...
In article ,
"Brenda Ann" wrote:

"Telamon" wrote in message
.
..

I would say bandwidth. Large aspect ratio antenna elements have a
narrow
band of resonance. It seems to me that there are some companies out
there that have tower kits that run 3 to 4 wires on spreaders so the
electrical diameter of the tower is increased. This will allow the
tower
to have lower VSWR over the +/-15KHz required.

I've been in on installing one of those kits.. lot of fun when you have
the
backup tower for the station only a few dozens of yards away.. you don't
want to forget to connect that ground in at least two places on the way
down
the tower..

That's great. Tell us how it works out when you tune it up.

In about 1989, we put a unipole on WDSR 1340 in Lake City, FL. The tower was
actually over 90 degrees, but the base was nearly 100 feet offshore in the
lake (thus the city name). The brackish water had pretty much dissolved the
ground system after some 40 years, and we put down a large ground mesh in
the water around the tower, and put a unipole on. The folks form Tennessee
came down, and they supervised the rigger. they strapped the tower base
plate to ground with three 2" copper straps, and use experience, the known
impedance of the tower and the rigger to find a connect point. They were
close enough that only two minor moves of less than a meter fund the right
match, and the station was back on the air.

The unipole did increase coverage, in an area where ground conductivity is
horrible. We did not notice any audio change, good or bad. The only long
term bad thing is that the outriggers had to be retensioned a bit, and in
major storms flying objects could break the wires or dislodge the fiberglass
yardarms that held them away from the tower, and on one occasion breaking
the critters off at the tower mount. I would not want one in a hurricane
prone region, as it would fly off the tower at the first impact of airborne
aluminum siding or trash cans.

That's a good point. I didn't think about flying objects breaking the
tower wires on the extenders. Every engineering solution has its down
side.

--
Telamon
Ventura, California

"Telamon" wrote in message
...

That's a good point. I didn't think about flying objects breaking the
tower wires on the extenders. Every engineering solution has its down
side.

Then you will appreciate this: after one of the major gulf coast hurricanes,
in the 70's, an engineer from Miami was hired to settle some tower
destructions. One, which failed at about 80 feet and collapsed was examined.
The measurements on the damaged section that caused the failure exactly
matched the shape and mass of a cow which had been picked up and hurled into
the tower 80 feet over the ground. You can not designee for the occasional
flying cow.

On Oct 11, 10:41 pm, "David Eduardo" wrote:
"Telamon" wrote in message

...



That's a good point. I didn't think about flying objects breaking the
tower wires on the extenders. Every engineering solution has its down
side.

- Then you will appreciate this: after one of the major gulf coast
hurricanes,
- in the 70's, an engineer from Miami was hired to settle some tower
- destructions. One, which failed at about 80 feet and collapsed was
examined.
- The measurements on the damaged section that caused the failure
exactly
- matched the shape and mass of a cow which had been picked up and
hurled into
- the tower 80 feet over the ground. You can not designee for the
occasional
- flying cow.

Gives new meaning to "When Cows {Pigs} Fly"

am'er - watch-out for that tower ~ RHF

On Oct 12, 1:41 am, "David Eduardo" wrote:
"Telamon" wrote in message

...



That's a good point. I didn't think about flying objects breaking the
tower wires on the extenders. Every engineering solution has its down
side.

Then you will appreciate this: after one of the major gulf coast hurricanes,
in the 70's, an engineer from Miami was hired to settle some tower
destructions. One, which failed at about 80 feet and collapsed was examined.
The measurements on the damaged section that caused the failure exactly
matched the shape and mass of a cow which had been picked up and hurled into
the tower 80 feet over the ground. You can not designee for the occasional
flying cow.

What have you been listening to on shortwave lately?