"John N9JG" wrote in message
...
A wooden utility pole with a length of 40 feet above ground would do the
job for me. It's just that I am not sure how the neighbors would react. A
search of the web did show that there are fiber glass flag poles available
that have sufficient height, but I don't know if they can support the
weight of 100 feet of 3/4 in copper pipe and a 10-15 lb remotely tuned
capacitor inside a weather-proof box.

"Edward A. Feustel" wrote in message
...

"John N9JG" wrote in message
...
I am in the planning stage for a 160 meters compact loop antenna. A loop
antenna may not have metal nearby, so I am planning to use a wooden pole
to support the top of the loop. In the ARRL Antenna handbook, it states
that "W5QJR made a pole of 2 x 4-inch lumber with 1 x 4-inch boards on
either side to form an I section. He held the boards together with
1/4-inch bolts, 2 feet apart and tied rope guys to the top. This made an
excellent mast up to 50 feet high."

Does anyone have any comments on the feasibility of an unguyed pole
using this same type of construction? Naturally, a portion of the pole
would have to be underground, and perhaps set in concrete. What about a
50 feet pole, with 10 feet underground ,which would give you a 40 foot
mast?

An alternative would be to have a contractor install a 40 feet utility
pole, but I assume the wooden pole described above would be less of an
eyesore (to the neighbors) than a utility pole.

Any comments and advice will be appreciated.
John, N9JG

If you really want to have the "mast" unsupported, consider a 50-60'
telephone pole
properly installed (for your type of soil) with one end buried deeply.
Perhaps you could
use a fiberglass extension from its top to support the antenna.

It would be worth your while to have a mechanical engineer calculate your
design's survival
characteristics in high wind and compare it with 100 year records for
high wind speed. Also you
might consider the prospect of icing if you live in a northern climb -- I
assume that the mast
is at a corner of the loop.
Regards,
Ed, N5EI



John,
Would you be able to provide additional support from the bottom of the loop
to ground?
That might relieve the situation. Could you have the feed at the bottom
rather than at the top and
could the box be supported?

If you could support from the bottom and use a heavy walled copper pipe
which would provide
substantial rigidity, the fiberglass might work.

I suspect that the neighbors are not going to be enthusiastic about the
loop.
Regards,
Ed, N5EI

Thanks, Ed, for your comments. Yes, If I have a supporting pole in the lawn,
there is no reason why I couldn't also have a support directly below the
loop. The loop would be in the shape of an octagon, it would be fed through
either a 1/5 size coupling loop or a gamma match at the center of the bottom
side, and the series resonating tuning capacitor would be inserted at the
center of the top side.

The 3/4 inch copper pipe would be the same type that is used inside houses
and is quite rigid. I can not seem to find, by Goggling, the weight of
copper pipe. By going to the local Lowe's store and hefting a 10 feet length
of pipe, I estimate the weight of 10 feet of pipe as being somewhere in the
range of 1-3 lb.

"Edward A. Feustel" wrote in message
...

"John N9JG" wrote in message
...
A wooden utility pole with a length of 40 feet above ground would do the
job for me. It's just that I am not sure how the neighbors would react. A
search of the web did show that there are fiber glass flag poles available
that have sufficient height, but I don't know if they can support the
weight of 100 feet of 3/4 in copper pipe and a 10-15 lb remotely tuned
capacitor inside a weather-proof box.

John,
Would you be able to provide additional support from the bottom of the
loop to ground?
That might relieve the situation. Could you have the feed at the bottom
rather than at the top and
could the box be supported?

If you could support from the bottom and use a heavy walled copper pipe
which would provide
substantial rigidity, the fiberglass might work.

I suspect that the neighbors are not going to be enthusiastic about the
loop.
Regards,
Ed, N5EI

My Lowe's store sells two kinds of copper pipe. The less costly one is
harder, lighter and thinner. I began my antenna experients with the huskier
stuff and after it bent, replaced it with the thin material, which is
holding up OK so far.

The thinner material seems to have about the same weight per foot as
aluminum. I'm using copper instead of aluminum because it is easier to make
good electrical connections between the pieces.

Tom

"John N9JG" wrote in message
...
Thanks, Ed, for your comments. Yes, If I have a supporting pole in the
lawn,
there is no reason why I couldn't also have a support directly below the
loop. The loop would be in the shape of an octagon, it would be fed
through
either a 1/5 size coupling loop or a gamma match at the center of the
bottom
side, and the series resonating tuning capacitor would be inserted at the
center of the top side.

The 3/4 inch copper pipe would be the same type that is used inside houses
and is quite rigid. I can not seem to find, by Goggling, the weight of
copper pipe. By going to the local Lowe's store and hefting a 10 feet
length
of pipe, I estimate the weight of 10 feet of pipe as being somewhere in
the
range of 1-3 lb.

"Edward A. Feustel" wrote in message
...

"John N9JG" wrote in message
...
A wooden utility pole with a length of 40 feet above ground would do the
job for me. It's just that I am not sure how the neighbors would react.
A
search of the web did show that there are fiber glass flag poles
available
that have sufficient height, but I don't know if they can support the
weight of 100 feet of 3/4 in copper pipe and a 10-15 lb remotely tuned
capacitor inside a weather-proof box.

John,
Would you be able to provide additional support from the bottom of the
loop to ground?
That might relieve the situation. Could you have the feed at the bottom
rather than at the top and
could the box be supported?

If you could support from the bottom and use a heavy walled copper pipe
which would provide
substantial rigidity, the fiberglass might work.

I suspect that the neighbors are not going to be enthusiastic about the
loop.
Regards,
Ed, N5EI

The Lowe's store here was stocking Type L Hard 3/4" copper pipe 10' long for
$10. However, they only had one item in stock. I am guessing the demand for
construction material due to the recent hurricane will cause shortages and
higher prices.

"Tom Coates" wrote in message
...
My Lowe's store sells two kinds of copper pipe. The less costly one is
harder, lighter and thinner. I began my antenna experients with the
huskier
stuff and after it bent, replaced it with the thin material, which is
holding up OK so far.

The thinner material seems to have about the same weight per foot as
aluminum. I'm using copper instead of aluminum because it is easier to
make
good electrical connections between the pieces.

Tom