Aluminum tubing for vertical antenna
 

I took scrap pieces of aluminum tubing lying around, not being particularly
careful of sizes as along they fit snugly into adjacent pieces when they
were slotted. I used hose clamps. I made it 33ft and 3 inches tall (1/4
wave on 40). It has 32 radials of various lengths for the non-WARC ham
bands 40 meters and higher. 16 of them are 34 feet long for 40. SWR on 40
meters is 1.2 to 1 without any adjustment at 7100. The vertical covers the
entire band. I use a Palstar AT1500CV transmatch on other bands and run 700
watts when needed. I can work anything I can hear and I work tons of DX.
The antenna is very quiet for a vertical. The Palstar has no problem
matching this vertical on all bands 40 through 6 meters including WARC
though 12 meters is the trickiest. Works much DX on all bands whenever I
try Peter I Island, Kiribati, etc., though I use other antennas on bands
other than 40 cut appropriately. Cost of the antenna was $0.00. I used
scrap tubing, scrap #12 or thicker radial wire, leftover rope for 3 guys at
18 feet, leftover 4BTV base. This antenna has been up for months on a hill
at 1100 feet and survived 80 mph plus gusts.

"Hank Zoeller" wrote in message
...
Hello everyone,

I'm contemplating putting up a vertical antenna for HF use. I'm looking
at an approximate height of 30 feet or so. I am thinking of using
aluminum tubing (0.058" wall) in a 'telescoping' manner. Here are my
questions (so far):

1) Diameter. For wind resistance, should I start with something like 1
inch diameter and work down to 3/8 inch? Would the antenna be stronger if
I started with 2 inch diameter and worked down to 1-3/8 inch?

It would seem to me that the larger diameter might be better able to
withstand wind but it would also offer more resistance to wind possibly
negating the additional strength. But, I have no experience to draw from.
So, fat or slim?

2) I am planning a set of guy ropes at about the 12 foot level, a bit over
1/3 height. Is there a better height for guy ropes? I can put as much
concrete in the ground as I like, and a very robust mount system is
possible. Is there any way to make an unguyed 30 footer that isn't a
tower form factor? Something like making the bottom 12 feet or so from 2
inch diameter, 1/4 inch wall tubing and then light weight tubing from
there up to full height?
--
73, Hank

Aluminum tubing for vertical antenna
 

Jozef wrote:
I took scrap pieces of aluminum tubing lying around, not being particularly
careful of sizes as along they fit snugly into adjacent pieces when they
were slotted. I used hose clamps. I made it 33ft and 3 inches tall (1/4
wave on 40)... The Palstar has no problem
matching this vertical on all bands 40 through 6 meters including WARC
though 12 meters is the trickiest.

That antenna is 5/8 wavelength on ~17.5 MHz. Above 21 MHz,
most of the radiation is lost at a high elevation angle.
Such an antenna is a poor performer on 15m, 12m, 10m, and
6m. Matching doesn't mean much for a monopole appreciably
longer than 5/8 wavelength.
--
73, Cecil http://www.qsl.net/w5dxp

Aluminum tubing for vertical antenna
 

Cecil Moore wrote:
Jozef wrote:
I took scrap pieces of aluminum tubing lying around, not being particularly
careful of sizes as along they fit snugly into adjacent pieces when they
were slotted. I used hose clamps. I made it 33ft and 3 inches tall (1/4
wave on 40)... The Palstar has no problem
matching this vertical on all bands 40 through 6 meters including WARC
though 12 meters is the trickiest.

That antenna is 5/8 wavelength on ~17.5 MHz. Above 21 MHz,
most of the radiation is lost at a high elevation angle.
Such an antenna is a poor performer on 15m, 12m, 10m, and
6m. Matching doesn't mean much for a monopole appreciably
longer than 5/8 wavelength.
--
73, Cecil http://www.qsl.net/w5dxp

I have an almost identical vertical with a relay controlled loading
coil I switch in for 160 and 80M and a SGC tuner.

Works great 160 to 30M.

Marginal at 20M and goes to poor from there up.

--
Jim Pennino

Remove .spam.sux to reply.

Aluminum tubing for vertical antenna
 

I understand that which is why in my original post I said, "Works much DX on
all bands whenever I
try Peter I Island, Kiribati, etc., though I use other antennas on bands
other than 40 cut appropriately." Perhaps, you missed that? Theory
granted, you're also make a case against success. It works. Though as you
suggest, with handicaps.


"Cecil Moore" wrote in message
.com...
Jozef wrote:
I took scrap pieces of aluminum tubing lying around, not being
particularly careful of sizes as along they fit snugly into adjacent
pieces when they were slotted. I used hose clamps. I made it 33ft and 3
inches tall (1/4 wave on 40)... The Palstar has no problem
matching this vertical on all bands 40 through 6 meters including WARC
though 12 meters is the trickiest.

That antenna is 5/8 wavelength on ~17.5 MHz. Above 21 MHz,
most of the radiation is lost at a high elevation angle.
Such an antenna is a poor performer on 15m, 12m, 10m, and
6m. Matching doesn't mean much for a monopole appreciably
longer than 5/8 wavelength.
--
73, Cecil http://www.qsl.net/w5dxp

Aluminum tubing for vertical antenna
 

Roy Lewallen wrote:
For about 20 - 25 years I've had four verticals of about 33 foot height
in my back yard. They're free standing, no guys. They went through one
wind storm with gusts in the 80 mph range, and all other weather,
without damage. Each is made of three pieces of telescoping 6061-T6
tubing, 1-1/4, 1-1/8, and 1 inch diameter.

[trimmed]

Roy,

Thank you very much. There's nothing like tapping the experience of
others. I'm really happy to hear I can build a freestanding vertical!

(But, I'll buy some spare aluminum anyway..)
--
73, Hank

Aluminum tubing for vertical antenna
 

Jozef wrote:
I neglected to provide the following links:

http://www.metaphoria.us/hamradio/40monoband.htm for the 40 meter
monobander vertical
http://www.metaphoria.us/hamradio/4BTV.htm for the base with radials. The
radials are now covered by grass that I mow with a hand manual non-powered
Scott's push mower.

Jozef,

What did you use for staples for the radials?

Thanks,
--
73, Hank

Aluminum tubing for vertical antenna
 

Hank,

Just wanted to add that you don't need 1/4 inch wall stuff anywhere in
a 33 foot vertical.

If you have it lying around you could use it, but the extra weight
really isn't worth it. Same for reinforcing by thickening the tubing
on the inside.

A hollow tube 2" in diameter with 0.058" walls is about 3 times stiffer
than a SOLID 1" rod.

Now, strength and stiffness are two different things, but you're better
taking the aluminum and making a fairly thin wall tube of large
diameter if you're trying to make a strong, stiff element.

For the price of one 12 foot 1/4" wall 2" tube you can buy the whole
vertical in 2" 0.058 wall tubing and the next telescoping size for
joints.
1/4" wall would be good if you're going to guy it and put a tribander
on top!

I'd go with Roy's vertical design, in fact. My antenna was a mess of
found aluminum, tent poles, etc. Might have even been 7/8" now that I
think of it.

This means that Roy's bottom section, if 0.058 wall 1.25" diameter 6061
was at LEAST 3 times as stiff as my 7/8" OD 3/4" ID 1/16" wall stuff,
and that's assuming I was using a good, stiff grade of aluminum, which
I wasn't.

Incidentally, Cecil, I think the 12 footers are more expensive because
you can UPS ship 6 footers anywhere and can't do that with 12
footers... it may be that it's just cheaper to keep the 6 footers in
stock because the market is bigger. Could also be that it's cheaper
for TX Towers to get them in .... dunno. It's too bad though, 12 foot
continuous sections would be good for this sort of thing.



73,
Dan

Aluminum tubing for vertical antenna
 

Aluminum tubing for vertical antenna
 

"Hank Zoeller" wrote in message
...
Hello everyone,

I'm contemplating putting up a vertical antenna for HF use. I'm looking
at an approximate height of 30 feet or so. I am thinking of using
aluminum tubing (0.058" wall) in a 'telescoping' manner. Here are my
questions (so far):

1) Diameter. For wind resistance, should I start with something like 1
inch diameter and work down to 3/8 inch? Would the antenna be stronger
if I started with 2 inch diameter and worked down to 1-3/8 inch?

It would seem to me that the larger diameter might be better able to
withstand wind but it would also offer more resistance to wind possibly
negating the additional strength. But, I have no experience to draw
from. So, fat or slim?

2) I am planning a set of guy ropes at about the 12 foot level, a bit
over 1/3 height. Is there a better height for guy ropes? I can put as
much concrete in the ground as I like, and a very robust mount system is
possible. Is there any way to make an unguyed 30 footer that isn't a
tower form factor? Something like making the bottom 12 feet or so from
2 inch diameter, 1/4 inch wall tubing and then light weight tubing from
there up to full height?
--
73, Hank

http://www.valcom.ca/Guelph/products...b-u_photo.html This is
built for navy shipboard use so it may be "scary expensive." These are
virtually indestructible. You have to hit one with a crane boom to break
it. It is exactly what you described in your last paragraph. This size
whip covers 2 - 30 MHz with a tuner.

The Navy has used many 35-foot whips over the years. There were
five-section versions, but any you found now would probably be too corroded
to be of use.

Aluminum tubing for vertical antenna
 

Sal M. Onella wrote:
http://www.valcom.ca/Guelph/products...b-u_photo.html This is
built for navy shipboard use so it may be "scary expensive." These are
virtually indestructible. You have to hit one with a crane boom to break
it. It is exactly what you described in your last paragraph. This size
whip covers 2 - 30 MHz with a tuner.

The Navy has used many 35-foot whips over the years. There were
five-section versions, but any you found now would probably be too corroded
to be of use.

Actually, I *did* find one of those things!

http://www.american-milspec.com/p961.html

Alas, it's a bit too tall for my use. I'm thinking of using a 26' whip
with a remote coupler (Harris RF-601) for operating from 40 through 15
meters. Or, I might go to a 30' whip for ops on 60 through 18 meters.
I haven't made up my mind yet although I'm leaning toward the 26' version.

If I go that route I might pick up a commercial, little brother of that
massive Navy style whip - the Shakespeare 5300. It's sold as a 28' whip
but it's actually 26' as they use the bottom two feet for a mounting
sleeve. It's made for shipboard use but is substantially lighter than
the Navy 35' whip. It's only 2-3/8" in diameter, for example..

Time is a precious commodity, at the moment, but I still might roll my
own from Texas Towers Aluminum.

73,
--
HZ