A 23 ft antenna should be easy and cheap. I would get one of those old
Antron antenas that was so popular for CB. They are nearly as long as
you want and add a full length CB whip to the top replacing the
origonal whip should get you there or awful close. These were end fed
half wave antennas so you could remove the matching network at the
bottom and replace it with your own.



Another interesting possibility. Unfortunately, I live inthe boonies.
Will look at those CB antennas on the WEB, but purchasing such an antenna
new would probably negate the money savings I'm trying to accomplish by
building a copy of a marine HF antenna to begin with!


Ed

"Ed" wrote in message
. 192.196...


IF ... you go with any kind of socketing arrangement for joining the
PVC sections, then Mr. Gravity will be your friend -- hose clamps
only.

Related: I didn't go to the home improvement store today to check
availability, but I gave some thought last night to PVC parts that
might make a base. There are some elbow and three-way fittings that
might be adaptable to forming a base. Do you need a way to keep the
thing sorta vertical and/or keep the bottom from kicking out and
toppling the whole thing? It's got to be relatively free-standing
(away from the body of your RV), right?


It is my intent to have some sort of either removable, or possibly
semi-permanent mount fastened to the rear bumper of my motorhome to hold
this verticle antenna. It will be located close to the ladder on the
back of the motorhome and the vertical antenna will be supported in one
place at the top of the ladder with a nylon marine type support bracket
made for that purpose.

Until I figure the actual hardware that will be on the bottom of the
bottom section of this antenna, I will hold off on the actual design of
the base support portion of this project.

Ed

Hi Ed

I use alot of PVC pipe to get my VHF antennas up in the air. It is my
opinion that a 23 foot tall structure made from hardware store quality PVC
will never make you happy, especially of it is made of 3 disassembalble
sections. PVC bends over alot in the wind, especially on warm days.

Jerry

I use alot of PVC pipe to get my VHF antennas up in the air. It
is my
opinion that a 23 foot tall structure made from hardware store quality
PVC will never make you happy, especially of it is made of 3
disassembalble sections. PVC bends over alot in the wind, especially
on warm days.


Point taken. One of the reasons I had considered putting copper tubing
inside... both to act as the radiator, and also to stiffen the PVC.


But.... see my next posted comment on this subject.

Ed

My thanks to all who responded to my query on this subject. After much
thought, and numererous replies with good info, I have decided it is just
not economically feasible to either purchase a marine HF antenna, ( ~ $150
), nor build a copy of one due to the expense of materials and labor.

I have decided to take the suggestions of many of you and just use
telescoping aluminum tubing to get my ~23 foot radiator and nevermind the
aesthetics of the pretty white Shakespeare 393 antenna.

Again, thanks to all.


Ed K7AAT

Jeff wrote:
I would recommend getting a glass fibre fishing rod and sliding copper braid
Why not copper foil tape?
3M has several widths in both conductive and non-conductive adhesive
used for shielding.

braid has that horrible "corrosion between the strands causing problems"
issue, although if it's new, and you're glassing over it, it might not
be a problem.

Or, why not just run a bunch of magnet wire...


over it, then getting some thin glass fibre tape and resin and taping over
the braid. This is how some military vehicle whips are constructed. You can
then paint it if you wish.

73
Jeff
G8HUL

Ed wrote:
I would recommend getting a glass fibre fishing rod and sliding copper
braid over it, then getting some thin glass fibre tape and resin and
taping over the braid. This is how some military vehicle whips are
constructed. You can then paint it if you wish.


Such an antenna would be excellent for my purposes if it is about 23
feet tall, except I need to break it down into three 7 1/2 foot sections
for storage inside an 8 foot PVC tube. I don't know if those long fishing
poles break down as such, do they?

Also, I do recall pricing such long poles in the past and the cost of
such may be approaching the cost of just buying an actual marine HF antenna
such as I wish to copy.


Ed

Check out Crappie or Panfish poles at a big online source like Cabelas.
You can get a (fairly light duty) collapsible 20 foot pole for $20.
They're Black Widow brand, and collapse to less than 4 feet.

Check out Crappie or Panfish poles at a big online source like
Cabelas.
You can get a (fairly light duty) collapsible 20 foot pole for $20.
They're Black Widow brand, and collapse to less than 4 feet.



Wished I'd found that one when I was searching poles on Cabelas' web
site the other day. As it is, I've got aluminum tubing currently on
order. Will definitely keep this inexpensive pole in mind, though, for the
future or another project.


Ed

In article 96,
Ed wrote:


I would recommend getting a glass fibre fishing rod and sliding copper
braid over it, then getting some thin glass fibre tape and resin and
taping over the braid. This is how some military vehicle whips are
constructed. You can then paint it if you wish.

Such an antenna would be excellent for my purposes if it is about 23
feet tall, except I need to break it down into three 7 1/2 foot sections
for storage inside an 8 foot PVC tube. I don't know if those long fishing
poles break down as such, do they?

Also, I do recall pricing such long poles in the past and the cost of
such may be approaching the cost of just buying an actual marine HF antenna
such as I wish to copy.


Ed

A few things you really need to look at A

Just how efficent do you think your 23Ft Antenna is going to be
on MF/HF?
What kind of RF Ground are you going to use to support this 23Ft
MF/HF Antenna?
You of course realize that ANY Antenna isn't going to do Diddle
Squat if your RF Ground is POOR, no matter how much you spend
or save, building it........

Bruce in alaska
--
add a 2 before @

A few things you really need to look at A

Just how efficent do you think your 23Ft Antenna is going to be
on MF/HF?
What kind of RF Ground are you going to use to support this 23Ft
MF/HF Antenna?
You of course realize that ANY Antenna isn't going to do Diddle
Squat if your RF Ground is POOR, no matter how much you spend
or save, building it........



First of all, you need to realize this is a MOBILE antenna, even if
only intended for operation while parked. Secondly, I have already used
a homebrew 12' tall Texas Bugcatcher type antenna with excellent results.

The antenna is mounted on the back end of a motorhome, and the ground
side of the antenna base is well bonded to the chassis underneath with 2
inch ground strap. So far, such mounting has worked well for me. My
intent is simply to build a newer, somewhat taller antenna for increased
performance.... primarily on 75 and 40M.

"Ed" wrote in message
. 192.196...

A 23 ft antenna should be easy and cheap. I would get one of those old
Antron antenas that was so popular for CB. They are nearly as long as
you want and add a full length CB whip to the top replacing the
origonal whip should get you there or awful close. These were end fed
half wave antennas so you could remove the matching network at the
bottom and replace it with your own.



Another interesting possibility. Unfortunately, I live inthe boonies.
Will look at those CB antennas on the WEB, but purchasing such an antenna
new would probably negate the money savings I'm trying to accomplish by
building a copy of a marine HF antenna to begin with!


Ed

They are pretty cheap, You gave me an idea. I have one and think I will
extend the length of it from the bottom with some conduit and make a 40
meter vertical.