Building a marine type HF whip
 

I wish to build a 23 foot whip antenna similar to the Shakespeare 393 HF
marine antenna, ( quite pricey ). It must be in three 7 1/2 foot long
sections and screws together, as shown he http://shakespeare-
marine.com/antennas.asp?antenna=393

I'm thinking along the lines of a 7 1/2 foot stainless steele whip on
top of two 7 1/2 foot long segments of my own construction. At present,
I think the two bottom sections would be copper tubing, enclosed within
PVC pipe. Although I have some ideas for the connections, I would like
to hear from others their ideas on both the building of two stiffer bottom
sections for this whip, along with ways of fabricating the screw-together
connections that would be both electrically sound and sturdy. The whip
will be for fixed mobile operation at a motorhome. The entire assembly
must break down and fit within a larger 8 foot long PVC tube for storage.

I realize I could go with telescoping aluminum tubing, but I prefer
something more elegant, such as this marine antenna.

Ed K7AAT

Building a marine type HF whip
 

i would go with 3 8' pieces of aluminum tubing telescoped. probably 5/8",
1/2", and 3/8". for temporary fixed operation that would be plenty strong
enough and would easily pack in a small tube. joints are easy to make with
a hacksaw and hose clamps and can easily be tuned by loosening a clamp and
sliding the joint a bit.

"Ed" wrote in message
. 192.196...


I wish to build a 23 foot whip antenna similar to the Shakespeare 393 HF
marine antenna, ( quite pricey ). It must be in three 7 1/2 foot long
sections and screws together, as shown he http://shakespeare-
marine.com/antennas.asp?antenna=393

I'm thinking along the lines of a 7 1/2 foot stainless steele whip on
top of two 7 1/2 foot long segments of my own construction. At present,
I think the two bottom sections would be copper tubing, enclosed within
PVC pipe. Although I have some ideas for the connections, I would like
to hear from others their ideas on both the building of two stiffer bottom
sections for this whip, along with ways of fabricating the screw-together
connections that would be both electrically sound and sturdy. The whip
will be for fixed mobile operation at a motorhome. The entire assembly
must break down and fit within a larger 8 foot long PVC tube for storage.

I realize I could go with telescoping aluminum tubing, but I prefer
something more elegant, such as this marine antenna.

Ed K7AAT

Building a marine type HF whip
 

i would go with 3 8' pieces of aluminum tubing telescoped. probably
5/8", 1/2", and 3/8". for temporary fixed operation that would be
plenty strong enough and would easily pack in a small tube. joints
are easy to make with a hacksaw and hose clamps and can easily be
tuned by loosening a clamp and sliding the joint a bit.


Dave,

That's probably the sane way to do it. I really wanted a Shakespeare
marine antenn clone, but the costs, or the labor involved is definitely
more than just doing the aluminum tubing thing.

Thanks.

Ed

Building a marine type HF whip
 

"Ed" wrote in message
. 192.196...


I wish to build a 23 foot whip antenna similar to the Shakespeare 393
HF
marine antenna, ( quite pricey ). It must be in three 7 1/2 foot long
sections and screws together, as shown he http://shakespeare-
marine.com/antennas.asp?antenna=393

I'm thinking along the lines of a 7 1/2 foot stainless steel whip on
top of two 7 1/2 foot long segments of my own construction. At present,
I think the two bottom sections would be copper tubing, enclosed within
PVC pipe. Although I have some ideas for the connections, I would like
to hear from others their ideas on both the building of two stiffer bottom
sections for this whip, along with ways of fabricating the screw-together
connections that would be both electrically sound and sturdy. The whip
will be for fixed mobile operation at a motorhome. The entire assembly
must break down and fit within a larger 8 foot long PVC tube for storage.

Ed, I have been thinking of a self-supporting whip, too and I am also going
to try big PVC, which is pretty rigid per unit length. I think adjacent
sizes would fit smaller-into-larger with two or four slots several inches
long cut into the larger pipe. Your application might use two sections of,
say, 1 1/2-inch PVC pipe, each 7 1/2 feet long and a shorter coupling piece
of 1 1/4-inch PVC pipe where they butt together. The large pieces would
have linear slots cut into them, with hose clamps on each side of the
coupling. (Lest anyone think I was neglecting pipe couplings that are made
for PVC -- no -- I just don't think they'd be very strong.)

This is all theoretical, mind you, as I have yet to put any pipe together,
myself. I have already thought of several variants, including: (a) using
a coupling piece larger than the two 7 1/2 foot sections, rather than
smaller and (b) making the lower 7 1/2 foot section larger than the upper
one, slotting just the lower one and thus omitting the coupling piece.

PVC has the advantage of having numerous adapter/reducer combinations to get
you to a suitable fitting for the base of your intended stainless steel whip
top section.

Question: What would you gain with copper tubing inside your lower PVC
sections. Slight BW increase, perhaps? It seems to me that it creates an
attachment problem, compared to just dropping a single conductor down from
the stainless steel whip, through the center of the PVC and out to the tuner
attachment. Speaking of that, including a PVC T-connector in the lower
section, perhaps a few feet off the ground, would give you an exit point for
the radiating element, but it would probably louse up the process of storing
the whole thing inside your 8 foot PVC tube (whose diameter is not given).

"Sal"

Building a marine type HF whip
 

Question: What would you gain with copper tubing inside your lower
PVC sections. Slight BW increase, perhaps? It seems to me that it
creates an attachment problem, compared to just dropping a single
conductor down from the stainless steel whip, through the center of
the PVC and out to the tuner attachment. Speaking of that, including
a PVC T-connector in the lower section, perhaps a few feet off the
ground, would give you an exit point for the radiating element, but it
would probably louse up the process of storing the whole thing inside
your 8 foot PVC tube (whose diameter is not given).


Sal,

Thanks for your ideas. Regarding the copper tubing issue, I was
thinking of that for two reasons.... good rigidity for the PVC to prevent
flexing, and also perhaps a better radiator. However, in raising the
question, you have prompted me to rethink that issue. Perhaps just
running some braid off of RG8 type coax in the PVC would be better in
some respects, including weight. Will keep pondering this issue.

My other problem will be to find a proper way to fasten/screw the
three elements together.

Perhaps just a PVC flat end cap on the top section with a 3/8-24 bolt
sticking up to fasten the SS whip to the top piece. As far as the other
two 7 1/2 foot sections go, I could simply do as you just suggested -
use a slightly smaller PVC piece at the middle juncture, glue it into
one of the two PVC sections, and simly pull it appart to dissassemble
those two sections. If I run braid down those two sections, I can just
leave it and fold the two PVC sections together to keep their storage
length at 7 1/2 feet long.

..... that would work. Problem is, I like the elegance of the
Shakespeare antenna, but I don't want to pay the price for one!

Ed

Building a marine type HF whip
 

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.

73
Jeff
G8HUL

Building a marine type HF whip
 

"Ed" wrote in message
. 192.196...


I wish to build a 23 foot whip antenna similar to the Shakespeare 393 HF
marine antenna, ( quite pricey ). It must be in three 7 1/2 foot long
sections and screws together, as shown he http://shakespeare-
marine.com/antennas.asp?antenna=393

I'm thinking along the lines of a 7 1/2 foot stainless steele whip on
top of two 7 1/2 foot long segments of my own construction. At present,
I think the two bottom sections would be copper tubing, enclosed within
PVC pipe. Although I have some ideas for the connections, I would like
to hear from others their ideas on both the building of two stiffer bottom
sections for this whip, along with ways of fabricating the screw-together
connections that would be both electrically sound and sturdy. The whip
will be for fixed mobile operation at a motorhome. The entire assembly
must break down and fit within a larger 8 foot long PVC tube for storage.

I realize I could go with telescoping aluminum tubing, but I prefer
something more elegant, such as this marine antenna.

Ed K7AAT


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.


Jimmie

Building a marine type HF whip
 

"Jeff" wrote in message
. com...


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.

73
Jeff
G8HUL


Yeah, I used to frequent a place that had parts for people who like to make
ther eown fishing rods. They had a lot of great stuff that would be useful
for makeing antennas. I would think something like this should be available
on the internet.

Jimmie

Building a marine type HF whip
 

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

Building a marine type HF whip
 

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

Building a marine type HF whip
 

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

Building a marine type HF whip
 

"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

Building a marine type HF whip
 

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

Building a marine type HF whip
 

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

Building a marine type HF whip
 

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

Building a marine type HF whip
 

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.

Building a marine type HF whip
 

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

Building a marine type HF whip
 

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 @

Building a marine type HF whip
 

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.

Building a marine type HF whip
 

"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.

Building a marine type HF whip
 

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.

My current 40 meter vertical is two 10 foot sections of steel TV mast
with an 18 foot CB antenna to total 28 feet. On the project list is to
add another 5 feet of mast but I will still use a tuner to get to 80 &
160 any way!

It is pretty sturdy.

John Ferrell W8CCW
"Life is easier if you learn to
plow around the stumps"