I posted the following question regarding the mechanical
constuction of a 160 meter vertical to the towertalk reflector.
Bill N4RN suggests I also post it to the topband reflector.
The responses on towertalk ran the gamut as is usual on the
'net. I have attached the original question below along
with the best (IMHO) responses. If you also read towertalk,
sorry for seeing this again and if you responded, thanks.
Rick Karlquist N6RK
rick@area.com
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QUESTION:
>My situation is slightly different than most of you. I do *not*
>have or plan to get a tower with Yagi(s) for 40 thru 10 meters.
>Hence I do not have a skyhook from which to hang a 160 meter vertical.
>I would like to simply build a dedicated 160 meter vertical,
>perferrably at least 90 feet high. Of course, I could get 9 sections
>of Rohn 25, but that would be overkill (I guess), and I don't want
>to do any climbing. Would it be possible to get say 40 feet of aluminum
>tower sections and attach 50 feet of aluminum tubing to the top, say
>2 inch with .120 or .058 wall? Could this be walked up, assuming helpers
>on the guy ropes? BTW, it is not a problem to have to guy this tower.
>Seems like this might work, but I haven't actually heard of anyone
>doing it. I would probably put a loading coil in series electrically
>between the top of the tower proper and the tubing extension (center
>loading).
>
>Rick Karlquist N6RK
>rick@area.com
I should add that the only trees I have are on the property line,
so I can't use them to support the vertical if I want a decent
set of radials.
RESPONSES:
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From: Bill Loviska <n4rn@gate.net>
Rick, you might also present your question to the group at
topband@contesting.com
I'm sure you will get all the help you can stand, and more.
Your idea sounds like fun to me, GL.
Bill N4RN
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From: W7lr@aol.com
Gm Rick. My 160m antenna is 90 feet tall made of 4 inch od aluminum
irrigation pipe. For a little top loading the top guys have 42 feet of wire,
the rest of the guys are nylon rope. Use L networks at base for 160 and 80.
(Could use 40 too, but have a seperate lazy-v for 40). Not too hard to get
it up, with good "hinge" at base, a few temporary sky hooks, and lots of
help. Reinforce joints with wooden fence posts inside, with 5 or 10 foot
long splices of aluminum tubing, and lots of hose clamps. Works great. 73
Bob W7LR
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From: "Roy S. Maull" <rmaull@access.mountain.net>
One of the fellas here has an inverted L for 160 that uses well casing
for the vertical section. This section is over 80 feet, and because the
sections are connected with screw-together sleeves is fairly rigid,
although it does require guys. He has four sets of four guys on it that
have an insulator very close to the pipe so they are not really part of
the antenna. The installation is done by pushing up and adding from the
bottom. This needs a bunch of hands to work the guys while pushing up,
but makes it easier than trying to walk up that much length.
Just an idea for you for what it is worth..
73, and GL with the project.. Roy N8YYS
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From: Guy Hamblen <tel1gah@is.ups.com>
Rick: I read your thread on 160m TowerTalk archives as I am not
actively on the reflector (too many messages...). Anyway, I have built
80 and 160 m verticals over the last 3 years using 2" x .058 alum tubing
with great success. In fact, I wrote an article on the 80m design for
the ARRL Antenna Compendium V. 65' of alum tubing for 1/4 wave on 80 m
was easy with guyline help during the raising; 90' of alum tubing with a
dipole capacity hat for 160m is much more challenging. I adopted an
design idea from ON4UN's recent book for a 160m. It worked very well as
designed.
This summer I added an 80m trap at the top so I could load the 90' on
80m. Using alum tubing is possible but *challenging* because it is
"wobbly" but with help on guy wires during the raising, it goes up
easy. Added advantages....inexpensive and a low visual impact. The
design of the trap is more difficult because it's resonant bench
frequency will differ when it is installed...stray capacitance, etc.
Use wire capacity hats instead of loading coils as K1VR suggests...much
more efficient. Save the base for your matching network and the MILES of
ground radials! Continue to try your idea....the performance will be
worth it.
Regards, Guy Hamblen, N7UN/2 (ex AA7QZ)
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