"Bob" wrote in message
...
I would like most practical sizes or options for transmitting on all bands
with my antenna tuner and ability to use all bands. The tower idea sounds
interesting, any links that explain this further?
THanks

You'll need a good ground system to load a tower, and unless you shunt-feed
it, you'll have to insulate it from ground as well. The good news is that
it'll be fairly effective as a radiator if you do put the effort into the
ground radials.

HTH.

Bill

What would be the optimum height of such a tower?

William Warren wrote:
"Bob" wrote in message
...

I would like most practical sizes or options for transmitting on all bands
with my antenna tuner and ability to use all bands. The tower idea sounds
interesting, any links that explain this further?
THanks


You'll need a good ground system to load a tower, and unless you shunt-feed
it, you'll have to insulate it from ground as well. The good news is that
it'll be fairly effective as a radiator if you do put the effort into the
ground radials.

HTH.

Bill

Ray Collins wrote:

What would be the optimum height of such a tower?

That depends. What is the lowest frequency on which you wish to transmit?

--
John Miller
Email address: domain, n4vu.com; username, jsm

The cost of living has just gone up another dollar a quart.
-W.C. Fields

20 meters. Is it just like AM tower arrays, ground radials as long as
the tower is high at every degree of the compass?

John Miller wrote:
Ray Collins wrote:


What would be the optimum height of such a tower?


That depends. What is the lowest frequency on which you wish to transmit?

Ray Collins wrote:
20 meters. Is it just like AM tower arrays, ground radials as long as
the tower is high at every degree of the compass?

If it were me I'd hang 3 separate dipoles, inverted vees or quarter-wave
slopers off of the tower. The tower shunt feed scheme works fairly well
on 40/80 but I've never had much luck at 20 and above.

My 2c.

-Bill

".Bill M" wrote in message
...
Ray Collins wrote:
20 meters. Is it just like AM tower arrays, ground radials as long as
the tower is high at every degree of the compass?

If it were me I'd hang 3 separate dipoles, inverted vees or quarter-wave
slopers off of the tower. The tower shunt feed scheme works fairly well
on 40/80 but I've never had much luck at 20 and above.

What ground system do you use? I've heard various reports about how many
radials are needed, and where/if they must/should be connected at places
other than the center: the only "hard" documentation is on AM broadcast
antennas, and I don't have the budget to buy space next to a salt marsh ...

Bill

William Warren wrote:
".Bill M" wrote in message
...

Ray Collins wrote:

20 meters. Is it just like AM tower arrays, ground radials as long as
the tower is high at every degree of the compass?

If it were me I'd hang 3 separate dipoles, inverted vees or quarter-wave
slopers off of the tower. The tower shunt feed scheme works fairly well
on 40/80 but I've never had much luck at 20 and above.


What ground system do you use? I've heard various reports about how many
radials are needed, and where/if they must/should be connected at places
other than the center: the only "hard" documentation is on AM broadcast
antennas, and I don't have the budget to buy space next to a salt marsh ...

Bill



I had a 40 meter vertical with 60 radials that really kicked butt.
Outperformed a nearby ham's 3 el "contest station" yagi in most every
case for the real long-haul stuff.

My son and I put the radials in progressively - the ant was located in
the bush in rocky terrain and was nothing more than a push up TV mast
balanced on a coke bottle and guyed with nylon rope. After about 2
dozen radials the difference wasn't really noticeable and this jives
with results I've heard from other people.
A 20 meter vertical (those push up masts are frequency agile-hehe) at
the same location was a dud compared to an A3 on a 15 foot mast further
down the hillside.

I shunt fed a tower once (60 ft with triband quad on top), no particular
ground system. Many of these schemes involve 'tuning' the ground lead
in order to get them to work. I got it to work on 40, can't recall how
80 acted but it wasn't near as good as a 1/4 wave sloper from the top of
the same tower and it kept the shack hot with RF. Again, it was a dud
on 20 and above. My guys were grounded and that seems counter-intuitive
for a vertical radiator.

I'm of the mind, based on my experience, that ground-mounted 20-15-10
stuff just isn't very effective compared to say a ground plane scenario
where the antenna can be elevated. And then that raises the question
whether or not an inverted vee at the same height as a ground plane is
more effective. I'm not sure there's an answer to that question but
vees and dipoles are easier to construct at the top of a tower :-)

-Bill M