Thanks for all the feedback... both positive and negative. I must say,
towertalk is one
of the best ham reflectors on the net.
I am planning to put up 4-squares for 80 and 40. From the responses, it
looks like
I'll either go for a fence top rail or a Rohn telescoping mast for 40
meters, with 4
elevated radials on each. I just found a good deal on two Force 12 180BV
verticals
for 80, so, will start with a pair of those & elevated radials on 80m. I'll
let you know how
it works out.
73,
-Gerry, W1VE/VE1RM
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Hull Computer Consulting
Applications Development Services
Greenfield, NH 03047 USA
email: windev@inetmarket.com
Web: http://www.inetmarket.com
eMail Page: pageme@inetmarket.com
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For those who were interested, here's what I received about using EMT
electrical conduit for a 40m vertical:
PROs
=====
"Take a look at my 40M 4-square made from EMT conduit at:
http://www.qsl.net/w0ma/jan.htm#FIFTH_STORY";
"get Nov. 1999 edition of CQ mag, see page 26, a flagpole antenna made of 2"
EMT"
"A suggestion- look into Rohn telescoping masts (mayybe also what RadioShack
sells.) I priced 30 foot locally at $38- 40 foot at $54. This stuff has the
fittings already on, and is simple push-up."
"And to the comment I would like to add: I would fill the bottle to
the top with oil, screw the cap, or push the cork back in, if you
live in a climate that reaches freezing during the winter.
Reason: I would suspect water could condense in bottle and freeze"
"Don't know if you've ever used wire for the vertical elements (can restrict
the bandwidth a little) or not, but I've used the pvc pipe available at
Lowes
to do verticals in the past. They have 20 foot 2 1/2" and 20/2" that slip
together. Put a wire down the side and place the bottom part on a metal
fence
post and you have a relatively inexpensive rustproof vertical. Also works
gret
for 30-40 foot masts. "
"I've used top rail poles for both 20 and 40 meter verticals and they work
GREAT. I use the top rails for mesh wire fence. They're about 10.5' long
My 20 meter (bird house support) consists of 1- 10' section with another
approx. 3.5 ' attached above it. The two sections are telescoped together
and then two bolts are through the joint (at 90 degrees to each other). Then
I mounted it on top of a 4' PVC pipe with 4 radials parallel to the ground.
I used a tough string for guying the pole. I painted the whole thing back
yard brown and it works great (for DX, not so good for close contacts).
During field day, we used 3 of these 10' poles together for 40 meters. The
only problem that we had was that the base wasn't high enough to decouple
the 4 radials from the ground so, the performance wasn't as good as the 20
meter version. I think that it would have worked OK at approx. 10' above
ground (as my wire 40 meter ground plane does).
The other alternative is to have it mounted at ground level and then use
8-16 1/4 wave radials on the ground.."
"for years I used the top rail that goes on a Chain Link Fence. The
Top Rail comes in 21ft (I believe) swaged sections. There are two diameter
sizes
that would interest you. 1 3/8 inch and 1 5/8 inch OD. I used the smaller
size for
40 meters and the larger for 80 meters. I erected a 4 square for 40 meters
and it took
6 of the 21 ft sections. At the time (several years ago) I paid about $7.95
per
section. All sections are galvanized, worked great and it lasts for years.
Try it, you will like it."
CONS
=====
"The problem is that the damned stuff is intended to bend - it is quite
thin-wall and the alloy used "takes a set" very readily. My bet is that
your verticals will buckle in the middle from the compressive force applied
by the guys."
"Conduit may be cheap, but it is made of mils steel and is very heavy. It
would not be my choice. First of all, you should be able to construct a 33
ft. mast of AL that would be self-supporting. The material may be a little
more costly, but you would avoid the cost of guys, the mess of having 4
guyed verticles to deal with. "
"PLEASE do not buy EMT for the verticals!!!
It is thin wall and not designed for vertical use.
Please see "aluminum" in their online catalog and order 6 foot sections
Start with largest size you wish and each section going smaller in size.
They fit together very well.Make a one inch (1") cut with hack saw or
saber saw. Then a 2nd cut 90 degrees off, for a total of 4 cuts.
Then buy stainless hose clamps to secure each section after it is 6"
inside."
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