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Posted: 10/24/2014 5:55:13 PM EDT
OK, let's make a simple dipole.  If you only have one dipole, I suggest you make it for the 40 meter band.  This band works
most of the day, sometimes all day, and well into the evening.  40 meters is a good regional band, reaching several states
away, and there are many active nets there, too.  (EDIT, I have talked to Ireland and Scotland on 40 meters at 01:00
local time, which was 06:00 their time.  Gray line?)  The 66' overall length can easily fit in many back yards, and with a little
help from a tuner, can also work 15 meters for some good DX.

I'm going to show a few photos of how to assemble a good, rugged dipole that will work as well as any commercially made
one, and is probably better constructed than most.

Here's where we start, with the Jetstream JTCE1 center insulator.  This one happens to be green, but they come also in black,
gray, and white.  Black disappears against foliage well, so if you have a nosy HOA, but have trees behind you, black works well.



I won't go into step by step, except to describe the components.  The clamps are small stainless cable clamps from True Value.  
Some are not stainless.  I found these in the marine section.  Try marine dealers for these in stainless.  While there, pick up a
good marine grade pulley, rather than a cheap one that will corrode and freeze up.  

In this case, the wire pigtails from cable clamps to the ring terminals are about 5" long.  I both crimped and soldered the
terminals, which come with the Jetstream insulator.  The JTCE1 has beveled holes that  won't cut through the wire or rope
used to hang the insulator.  Good thinking on Jetstream's part.  The same center insulator can also be used to make a fan
dipole, and more bands can be added later.  

Another thing I like about this center insulator is that it is easy to wrap the SO-239 / PL-259 with coax seal, silicone tape, or
other sealant method.

I put a drop of blue (removable) Locktite on each of the nuts on the cable clamps, and also the nuts on the terminals.  There is
some silicone dielectric grease smeared on the ring terminal before assembly.
Link Posted: 10/24/2014 5:57:17 PM EDT
[#1]
Measure from the center of the insulator out to where you will place your end insulators.  I know that the pigtails (they
are 5" long, leave some slack here) going to the terminals add a little more length, but we will take care of that when
we trim the antenna during testing.





This center insulator may be obtained from Universal Radio.  www.universal-radio.com

It is found in the catalog under Antenna Construction Supplies.

http://www.universal-radio.com/catalog/antsup/5524.html

Here is a very similar center and end insulator kit from Alpha Delta.  It contains a static discharge cartidge,
but is also much more expensive.

http://www.universal-radio.com/catalog/antsup/0297.html
Link Posted: 10/24/2014 5:59:23 PM EDT
[#2]
Here is one of the end insulators.  It is also found at Universal Radio listed simply as C150.  It looks like a generic
electric fence insulator.  Use any kind you like, but these are cheap and effective.

http://www.universal-radio.com/catalog/antsup/4818.html



Again, a drop of blue Locktite on the cable clamp nuts is a good idea.
Link Posted: 10/24/2014 6:05:16 PM EDT
[#3]
Measure  length of each leg from the middle of the center insulator, as shown previously, to
the farthest reach of the wire in the end insulator.




Wire used, in this case, was 14 ga stranded insulated THHN.  This antenna is being built for my
club, and is what they had.  I prefer MTW, but this wire is fine.


Calculate the overall span of your 1/2 wavelength dipole with the formula

468 / frequency(in mhz) = overall length in feet.

So, for 40 meters, centering the frequency in the band (7.000 - 7.300 mhz) at 7.150 mhz, we get

468 / 7.150 mhz  =  65.45'

So each leg will be  32.73'.  

I would add a few inches for the 40 meter band, and measuring as shown above, make each leg 33'.  We will adjust/correct for any error during installation.

Link Posted: 10/24/2014 6:07:46 PM EDT
[#4]
Nice job! I need to try one of those center insulators someday!
Link Posted: 10/24/2014 6:10:19 PM EDT
[#5]
This is our end result.




This one happens to be cut for 3.900 mhz, the center of the 75 meter phone portion of the 80 meter band,
but construction for any other frequency is similar.  I made each leg 60.5' long, overall span 121'.  We will
trim that a bit to get it up to 3.900 mhz by trimming the ends.  3.900 mhz should be 120' exactly, but it is
far easier to take a few inches off than to add a few inches if too short.


There are other center and end insulators.  Split bolts may be used in place of the cable clamps.

But this is one way to make a good, strong, long lasting dipole.
Link Posted: 10/24/2014 6:17:57 PM EDT
[#6]
An analyzer will make trimming fast and easy.

We will hang the dipole, check with the analyzer.  Let's say we find lowest SWR is 1.15:1 at 3.869 mhz.  We know overall
length now is 121'.  We will make a ratio and solve for the new length.

( Actual frequency / Frequency desired)  x Present Length = New Length

( 3.869 mhz / 3.900 mhz )  x  121'  =  120'

121' - 120' = 1' to be removed, or 6" removed from each side.

Do this, and you'll be right on the desired frequency.
Link Posted: 10/24/2014 7:49:22 PM EDT
[#7]
Very nice work.  Have you considered using a couple of quick links to make changing wires easier?  After I took this pic I started using a single quick link through the top eye bolt so that there was no strain on the sides of the plastic box.


Link Posted: 10/24/2014 8:30:38 PM EDT
[#8]
That's not how I do it.  I start with something perfectly fine like that, then I figure this could be better or that could be better . . . maybe I should just redesign this part and that part.  6 months later, I have a beautifully elaborate contraption that costs 5 times as much and performs half as well.  
Link Posted: 10/24/2014 8:39:20 PM EDT
[#9]
My center insulator is a 30-30 plastic cartridge holder. It works great. I just weaved the wire through the holes.
Link Posted: 10/24/2014 10:18:46 PM EDT
[#10]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Very nice work.  Have you considered using a couple of quick links to make changing wires easier?  After I took this pic I started using a single quick link through the top eye bolt so that there was no strain on the sides of the plastic box.

http://www.ar15.com/media/viewFile.html?i=69678
View Quote



For fast up/down of portable/emergency/field day antennas I make the legs removable by using snap hooks, such as on a dog leash, and single Anderson Powerpoles for
the electrical connection.



Link Posted: 10/24/2014 10:21:01 PM EDT
[#11]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
That's not how I do it.  I start with something perfectly fine like that, then I figure this could be better or that could be better . . . maybe I should just redesign this part and that part.  6 months later, I have a beautifully elaborate contraption that costs 5 times as much and performs half as well.  
View Quote




Link Posted: 10/24/2014 11:05:00 PM EDT
[#12]
tag.
Link Posted: 10/25/2014 11:58:53 AM EDT
[#13]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
That's not how I do it.  I start with something perfectly fine like that, then I figure this could be better or that could be better . . . maybe I should just redesign this part and that part.  6 months later, I have a beautifully elaborate contraption that costs 5 times as much and performs half as well.  
View Quote

But you had fun doing it!

It's often said that one learns more from their failures than from their successes. I've learned a Hell of a lot in my lifetime!
Link Posted: 10/25/2014 12:10:00 PM EDT
[#14]

Discussion ForumsJump to Quoted PostQuote History
Quoted:



But you had fun doing it!



It's often said that one learns more from their failures than from their successes. I've learned a Hell of a lot in my lifetime!

View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:



Quoted:

That's not how I do it.  I start with something perfectly fine like that, then I figure this could be better or that could be better . . . maybe I should just redesign this part and that part.  6 months later, I have a beautifully elaborate contraption that costs 5 times as much and performs half as well.  
But you had fun doing it!



It's often said that one learns more from their failures than from their successes. I've learned a Hell of a lot in my lifetime!

Yessir!  Building is 87% of the fun, which is why I don't plan to change my ways.  





Jupiter, I love the snap hook / PowerPole setup!  Our club Pres designed a modified AS-2259 with loading coils for me to build.  I'm going to steal that idea for it.





 
Link Posted: 10/25/2014 2:53:24 PM EDT
[#15]
Go right ahead!  Great for portable ops!
Link Posted: 10/25/2014 3:33:29 PM EDT
[#16]
Nice work OP

Discussion ForumsJump to Quoted PostQuote History
Quoted:
My center insulator is a 30-30 plastic cartridge holder. It works great. I just weaved the wire through the holes.
View Quote


Any pics?
Link Posted: 10/25/2014 5:24:49 PM EDT
[#17]
Listen to this man.  He knows of what he speaks.



Hey Jup, that OCF Dipole you forced me to build just got me Europe, Africa, and freakin' AUSTRALIA on 10M with 100 watts out of the 7200!
Link Posted: 10/25/2014 5:51:47 PM EDT
[#18]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Listen to this man.  He knows of what he speaks.

Hey Jup, that OCF Dipole you forced me to build just got me Europe, Africa, and freakin' AUSTRALIA on 10M with 100 watts out of the 7200!
View Quote



Hey, hey, hey!  What can I say?

Congrats!  


Link Posted: 10/25/2014 6:03:57 PM EDT
[#19]
OK, this morning my buddy Jim and I went up to the club station to hang this 75 m dipole from the tower.  There is an
angle iron arm (or is that aluminum?) coming out with a pulley to support the center insulator of the dipole.  

We had to replace the old 75 m dipole as it was intermittant.  Could not get the same analyzer readings twice in a row.  
SWR was all over the place from 1.1 to infinity and beyond.  

The previous dipole was ancient.  The plastic end insulators were cracking and chalky from UV.  The SO-239 socket was
visibly corroded.  The insulation was cracking off the wire.  It served us well but was time to go.

Made up the dipole you see in this thread.  Had the legs spread out, everything ready.  I even had a new PL-259, soldering
gun, solder, etc, to put a new end on the coax.  Plus dielectric silicone grease and silicone tape (seals to itself), to
waterproof it.  All was ready... then disaster struck!

The rope hung up on something about 40' up the tower.  Could not pull it either way.  We worked it, it was stuck and not
coming loose.  Went up on the fire escape landing beside the tower, used a long pole to hook the rope just above where
it was hung up, and were going to pull what we could, try to slip in new rope.  No dice, the tiny 1" pulley some idiot
installed up top would not allow that.  Then the rope slipped out of my hand and the final result is the rope is out of the
pulley on the ground.  Zzzzzzzzzzzzzzzzzzzzzzzzzzip!!!    SHOZBOT!!!

Just as the rope hit the ground, I mean exactly when, the club president drives up.  She gets out of the car, saw what
happened, shook her head, got back in and drove away.

Well, I'm too old and fat to climb the tower, reach out 4' and thread the pulley.  We have a bucket truck coming in a
few weeks to replace bearings on the stinger up top (the 10' pipe turned by the rotator, or "rotor" as many call it).  We'll
thread in new rope at that time.  We'll also put in a larger MARINE grade pulley.  (for corrosion resistance)

Meanwhile we are not out of business on 75 meters.  We have a 80-40-20-17-15-12-10-6 meter OCFD that will easily
do the 75 m portion of the band with tuner.  OCFD for the win!  [Kermit] Yayyyyyyyy!!!! [/Kermit]

So, that was today's antenna party adventure.

Link Posted: 10/25/2014 6:13:16 PM EDT
[#20]
I keep trying to get you to recruit a ham down there, he would have been over in 10 min to climb that tower.
Link Posted: 10/25/2014 6:44:38 PM EDT
[#21]
We have some new meat in the club.  Young guys.  One a fireman, the other does commercial
comms and tower work.  They are good at climbing towers.
Link Posted: 10/27/2014 10:43:30 PM EDT
[#22]
Final installation update.

Three club members and yours truly finished hanging the new 75 m dipole.  It is in place and operable.

One of the new guys climbed the tower and hung a new marine grade (corrosion resistance) 2" pulley with new black
(UV resistant) parachute cord for pulley rope.

We noted the corroded PL-259 on the coax, cut it back about 1 foot and observed the braid was clean and shiny, no
water contamination.  Soldered on a new PL-259.

Coax was screwed to the dipole center insulator using dielectric silicone grease (if there is no room for water to get in,
it can't) and wrapped with 1 layer of Scotch 3M 77 tape sticky side out (so it does not stick to the connector making
a gummy mess), then a layer of 3M 130C butyl rubber tape (bonds to itself - similar to "Coax Seal"), then another layer
of 3M 77 elec tape sticky side in.  A small ty-wrap put on to prevent tape from unraveling.

The entire assembly hoisted up, ends of the legs pulled out and tied off.

SWR check at 1.4:1 minimum at about 3.870 mhz.  This is a little low, but the legs were cut a little long on purpose,
easier to trim some off than to add wire.  We want it up around 3.900 - 3.910 mhz for the various regional nets at 3.902,
3,905, 3.907, 3.910, etc, and that is the middle of the 75 m phone portion of the band.

Copper wire stretches, so we'll let it sit a few months, then trim the ends to get it up to 3.900 mhz.  That will be a one
man job.  We'll check SWR and resonant frequency again in a year or so.

Finishing the 75 m dipole installation today was smooth and easy.  The entire operation took about a half hour.

Good job guys, with a special thanks to our tower climber!
Link Posted: 10/28/2014 9:30:36 PM EDT
[#23]
Awesome!

Link Posted: 10/31/2014 6:46:56 PM EDT
[#24]
A funny addition to this story...  

I told a ham friend, Ed, about this over the air a few nights ago.   I told him about dropping
the rope, things just not going the way we planned.

Ed is a minister.  Reverand Ed.  We elected him by acclaim as Chaplain of our net.  And Rev. Ed
blesses everyone on the net.  When Rev. Ed has blessed you, you've been blessed.  

Anyway, he said, "You know, I think there's a sermon in this."

"Really?" I replied.

"Yes," he said.  "When you get to the end of your rope DON'T LET GO!"
Link Posted: 12/22/2014 4:15:34 PM EDT
[#25]
Used this thread as a guide to build this for my first antenna:



More details here.
Link Posted: 12/22/2014 6:43:22 PM EDT
[#26]
Two thumbs up!!!

If you have not done it, drill a 3/32" hole in the bottom of the center insulator assembly right next to the connector.  
This "weep hole" will help drain any water condensate that may form.

This antenna and some parachute cord, you are ready to log some contacts!

Link Posted: 2/11/2015 11:59:04 PM EDT
[#27]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Used this thread as a guide to build this for my first antenna:

http://i62.tinypic.com/2j2stus.jpg

More details here.
View Quote



Well, made any contacts?
Link Posted: 2/12/2015 1:47:15 AM EDT
[#28]
Discussion ForumsJump to Quoted PostQuote History
Quoted:



Well, made any contacts?
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Quoted:
Used this thread as a guide to build this for my first antenna:

http://i62.tinypic.com/2j2stus.jpg

More details here.



Well, made any contacts?


I did.  It worked quite well on the digital modes as well as some voice contacts.  However, once I got my /AG I needed more antenna for the new bands so I put up a second hand G5RV jr.  I'll keep it, and will probably build upon it in the future to make it a multi-band setup using aligator clips or such to make it longer or shorter as needed.  Since it's stout enough I could use it as center point for a full 160 when I go camping or other field play.
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