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View Full Version : 2 meter dipole?. Where can I find one of these?



KJ6OJL
10-10-2011, 11:50 PM
I keep seeing some sweet deals on these two meter dipoles.
like this thread
http://forums.qrz.com/showthread.php?315863-2M-Dipole-and-2-Gonset-Communicator-Manuals&p=2356333#post2356333
Where can I find one of these at such a great price??
I looked for the company mentioned in the thread, but google brings lots of results which are not right..
73
KJ6OJL
Don

WB2WIK
10-10-2011, 11:58 PM
I don't know, but why not just make one? It's two pieces of wire with a center insulator, and only 40" long.

WA6MHZ
10-11-2011, 12:03 AM
a dipole is really ridiculous for 2 meters. it would work for testing, but for operation, you might as well put up either a J-Pole if you want vertical omni, or a small beam for horz sideband. No one I ever knew used a dipole. Only for the driven element of a beam. The seller is probably hoping to score a sale to a NEWBIE who has no idea how silly it is.

WB2WIK
10-11-2011, 12:07 AM
a dipole is really ridiculous for 2 meters. it would work for testing, but for operation, you might as well put up either a J-Pole if you want vertical omni, or a small beam for horz sideband. No one I ever knew used a dipole. Only for the driven element of a beam. The seller is probably hoping to score a sale to a NEWBIE who has no idea how silly it is.

That's pretty true. Used "vertically" (for FM) it's a horrible design because it's almost impossible to keep the coax from coupling to it and screwing it up badly. Used "horizontally" for SSB and other modes, it's fine but only works in two directions, so unless you can rotate it, you're missing out on more than half of what you might be able to work.

A 2m dipole is so short most would make one out of aluminum tubing (not wire) and put it on a rotator to take advantage of the gain it has in two directions.

K2WH
10-11-2011, 12:11 AM
7575575756757577575975758

Build one or 2 of these. One is for 2 meters and the other 70cm (440mhz). The white caps are PVC pipe caps sized to keep water out of the coax connector and radial hardware. These were used for 4 years with zero deterioration in the NNJ weather. All the elements are 1/8" silver solder rods. The brass balls from Grainger.

Click on the image.

K2WH

W5WPL
10-11-2011, 12:45 AM
I use a J-Pole leaning on the wall.
I'm 1 mile from the repeater.:)

WB2WIK
10-11-2011, 12:47 AM
I use a J-Pole leaning on the wall.
I'm 1 mile from the repeater.:)

For 1 mile you could probably install the j-pole inside the microwave and close the door.;)

N5PAR
10-11-2011, 12:50 AM
I use a J-Pole leaning on the wall.
I'm 1 mile from the repeater.:)

I have a j pole made from 300 ohm antenna twin lead. You can just hang it in a tree. I will give it to you if you drive up to Spring. I would like to meet you anyway. In reference to the other thread I can show you some sling shot tricks I learned while getting my HF dipole up.

W9OE
10-11-2011, 01:09 AM
My first antenna project was a 1/4 wave 2 meter ground plane using nothing more than a SO 239 connector. Properly cut ground plane element in each of the four holes on the base of the connector, soldered or bolted your choice. Properly measured and cut center radiator soldered into the terminal of the SO 239. A plastic SO 239 cap with small hole lowered and sealed at the bottom of the center radiator. DONE! Half hour of work and about 4 bucks for parts. It was used for about 3 years in the elements and worked just fine. It is still sitting on my shelf and can be put into service at any time.

KJ6OJL
10-11-2011, 04:24 AM
Wow, this thread took off faster than I expected.
What caught my eye about the 2 meter dipole was the ultra small size and portability, I have made a ground plane. I must give credit to WB2WIK who provided me the aluminum piece which was the start.
I have been very happy with it, have been able to hit a repeater 50 miles away.
As of now it's in my room and still able to hit plenty of repeaters in the area.

I am still unable to locate aluminum locally which is thick enough to build another.
My own excitement to build I should have cut the one I used in half and made two.
But it's doneand built.

I like the PVC cap idea very slick and great insulator idea!!

I will see if I can locate some plans on that 2 meter dipole. Yes
This may not be a great regular antenna but that is not what I am looking at one for.
More or less will be looking at something like that for camping and the sort. Something for easy setup and tear down. But ultra compact. I saw some plans out there for a small aluminum antenn but they were not very clear, or even detailed for that matter...

Great thing about being new to ham radio is I am willing to experiment and see what is a hit or miss..
Also looking to see what i can set up in my truck as well, that will end up being another thread.

Next hunt 2 meter dipole plans, and see what other plans can be made into something that small.
Seen the folding jpole another cool looking one.. But not super compact or covert for camping etc.

73
KJ6OJL
Don

KJ6OJL
10-11-2011, 06:46 AM
Do you have the plans on this one?? Sounds like a future project for me :)
73
KJ6OJL
Don



I have a j pole made from 300 ohm antenna twin lead. You can just hang it in a tree. I will give it to you if you drive up to Spring. I would like to meet you anyway. In reference to the other thread I can show you some sling shot tricks I learned while getting my HF dipole up.

KJ6EZQ
10-11-2011, 08:13 AM
According to http://www.kwarc.org/ant-calc.html , these are the dimensions to build a dipole.
Total length of the dipole will be 3.19 feet.
Each leg of the dipole will be 1.595 feet.

Take a wire, make it 3.19 feet long and cut it exactly in half at 1.595 feet. Connect the shield of a coax cable to one side and the center to the other side of the wire. That's all you really have to do to build a dipole, but I would make sure the coax stretches out perpendicular to the dipole so that they do not couple. Also, using it as a vertical would probably be best.

Don't let others discourage you. Have fun experimenting, I'm sure lots of folks will be interested to hear that you're using a dipole on 2m. Let us know how it turns out.

KJ6EUO
10-11-2011, 07:37 PM
What you want for camping/portable is a tv twin lead Jpole. It fits in a sandwich baggy weighs nothing and can be deployed easy.
http://www.fars.k6ya.org/docs/DBJ2_port_art.pdf
http://snovalleyarc.org/pdf/roll up J Pole.pdf (http://snovalleyarc.org/pdf/roll%20up%20J%20Pole.pdf)
http://w7sav.net/RadoShack_files/Build a J-Pole.pdf (http://w7sav.net/RadoShack_files/Build%20a%20J-Pole.pdf)
http://larc.hamgate.net/pocketJpole.htm
http://www.qsl.net/wb3gck/jpole.htm

VA3CQC
10-11-2011, 09:59 PM
No one I ever knew used a dipole.

Hey, I use a dipole! Maxrad MDA-1501

K8JD
10-11-2011, 11:12 PM
I m waiting for the guy who wonders if he makes a two meter dipole and uses his tuner, can he get out on 80 M since a dipole is a dipole, after all !!!!

N5PAR
10-12-2011, 12:35 AM
Do you have the plans on this one?? Sounds like a future project for me :)
73
KJ6OJL
Don

Below are the plans for the twin lead J pole. I have built several of these. I put about 15 feet of coax on it. Very handy like someone else said you can roll it up and put it in your pocket.



Here's what you'll need to build a 2 meter rollup portableantenna.

A 60-inch piece of flat TV twinlead. Use the inexpensive Radio Shack twinlead. Don't use the more expensive foam-filled line.
6 feet or more of coax cable. Use RG-58/U.
PL-259 connector.
Here's how you build it:

First, take the 60 inch piece of twinlead and strip back about 1/2 inch from one end. Twist and solder the two wires together. Keep the connection as short as possible. This will be the bottom of the antenna.
Next, measure up 1-1/4 inches from the bottom and carefully remove the insulation, exposing both wires, as shown in Figure 1. Keep the notches small (1/8" or so) and be careful not to cut the wires. This is where we will be attaching the coax later.


Now, attach your coax as shown in Figure 1.
Measure up 15-1/4 inches from the point where the coax braid is attached and make a 1/4-inch notch. This time, you want to cut through the wire. Only cut one notch and make sure it is on the side where the braid is attached. This will form the 1/4 wave matching section.
Tape the coax to the twinlead for strain relief. Also, tape all solder connections and add some tape at the 1/4-inch notch for added strength.
Now, measure up from the bottom of the antenna and cut it to an overall length of 54 inches.
That's about all there is to it. Tofacilitate hanging, punch a small hole in the top of the antenna. Usemonofilament fishing line or other non-conductive line through the hole forhanging.
75826

KJ6OJL
10-12-2011, 12:58 AM
More great information, and more future projects, but looking very forward to them..
the twin lead one looks very promising as a ultraportable solid performer.
I may end up building all three over next few months. As Some other side work is on its
way, I will end up posting all my results.

Next question, I have a SWR meter that was sold back when for CB radio, I borrowed it and it reads
1.2 swr on my ground plane antenna. but wondering how accurate should I consider it??
Looking at box, didn't think to until now it shows
CAT no. 21-523.
Field strength / SWR Tester
States Covers 3-30 MHZ up to 1000 watts.. hurmm 2 meter 146mhz.. guess I just answered my own question..
and I missed a Diesel on local crags for 5 bucks!!..
I could have kicked my self when I saw what I missed..

WB2WIK
10-12-2011, 01:02 AM
I wouldn't use any kind of j-pole, roll-up or otherwise; it's a highly compromised antenna.

Hams think everything "works great" when they can key up a repeater 100 miles away. Not realizing the repeater is doing all the work, and any sort of antenna would do that.

The j-pole in any form isn't a good design. It wastes space and has designed-in common mode problems.

A 1/4-wave ground plane, properly built, is actually a better antenna. It's also shorter.:o

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