| Author |
Message |
    
Mikefromms
Intermediate Member
Username: Mikefromms
Post Number: 294
Registered: 6-2003
| | Posted on Wednesday, November 24, 2004 - 6:56 pm: | 
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I have built a dipole and use 42ft of mini 8x as my coax. My swr is perfect and the antenna works over a large number of frequencies. More than I ever thought a dipole would. This thing is hearing great and getting out surprising well. I have it about 24 ft. at the top insulator and it kind of slants and the bottom wire hangs down a little more vertical. It's not perfectly vertical and has some horizontal qualities. Anyone else here ever have success with a vertical dipole for cb? Mine is not a v.
mikefromms |
Co_786
Junior Member
Username: Co_786
Post Number: 10
Registered: 2-2004
| | Posted on Thursday, November 25, 2004 - 12:54 am: |
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Is it a inverted V ???? |
Co_786
Junior Member
Username: Co_786
Post Number: 11
Registered: 2-2004
| | Posted on Thursday, November 25, 2004 - 11:36 am: |
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The vertical cb dipole is a starduster thats missing two legs. {with 20 extra ohms or so to deal with} |
AEdeathcharger336 (Unregistered Guest)
Unregistered guest
| | Posted on Thursday, November 25, 2004 - 12:11 pm: |
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dipoles are a tried and true design. not suprising |
The ELCO guy (Unregistered Guest)
Unregistered guest
| | Posted on Friday, November 26, 2004 - 8:54 am: |
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In addition, by slanting the dipole away from horizontal into an angle you use the earth as a kind of natural reflector. Kind of a small beam if you will.
The ideal configuration is to make the antenna perfectly strate and streach it out so the angle is about 45 degrees to the earth. The direction of preference will be in a line from the earth to the antenna. Just in case you are interested its called a Sloping Dipole.
That ELCO Guy |
Tech833
Moderator
Username: Tech833
Post Number: 893
Registered: 8-2002
| | Posted on Friday, November 26, 2004 - 11:52 am: |
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Mike,
You have discovered the 'secret weapon' of the antenna designers.
Now, just make variations to the basic dipole to get different characteristics you may want to remove ones you don't want. The dipole is the building block. That is why gain (at least in the commercial world) is compared to the dipole. |
Mikefromms
Intermediate Member
Username: Mikefromms
Post Number: 297
Registered: 6-2003
| | Posted on Friday, November 26, 2004 - 7:12 pm: |
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Yeap, it would be nice to put up 4 slopers-sloping in the 4 poles and put them on a switchbox. Copper has a heck of a deal on 41 feet of #14 gage copper wire, in case someone is interested.
mikefromms |
AEdeathcharger336 (Unregistered Guest)
Unregistered guest
| | Posted on Friday, November 26, 2004 - 10:02 pm: |
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hey mike, another thing you could try with dipoles is find the biggest phasing harness you can find for the dual trucker antennas and stack them vert. one on top of the other. this will give ya some gain |
Tech237
Moderator
Username: Tech237
Post Number: 121
Registered: 4-2004
| | Posted on Saturday, November 27, 2004 - 9:49 am: |
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Mike ,
If you cut the coax for each dipole to a certain length (I'd have to look up the length) and connect to a remote switchbox near the antennas the non active dipoles then act as reflectors for the one active antenna, thus giving some gain and directionability.
Used this approach for a commercial HF antenna near 40m some 15 years back, |
Kilowatt
Intermediate Member
Username: Kilowatt
Post Number: 113
Registered: 2-2004
| | Posted on Monday, November 29, 2004 - 4:07 am: |
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Hi Mike,
If you are in the mood to experiment, you can make that dipole into a loop by soldering the ends of the dipole together. (However, you will need to make the dipole twice as long as it is now to work on the same frequencies.)
I run loops here and find them MUCH quieter than dipoles. I've got lots of neighbors, and dipoles pick up a lot of RFI from their computers and other electronic appliances. My loops pick up about 1/10 of that garbage...
Just an idea if you feel like experimenting!
73
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Allagator
Advanced Member
Username: Allagator
Post Number: 515
Registered: 9-2002
| | Posted on Monday, November 29, 2004 - 4:04 pm: |
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HEY MIKE !!!!
build one out of aluminum add a boom and call it a GATOROD !!!! he he he i had to tell you that cause that is all my GATOROD is (Dipole) with a 8 foot standoff from the side of the tower !
next is the GATORBEAM !!!! LOL
gota love to experiment !!!!!
Allagator |
That Elco guy (Unregistered Guest)
Unregistered guest
| | Posted on Monday, November 29, 2004 - 5:46 pm: |
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237 is correct...
The basic setup is that you put up 4 dipoles each one tilted in the 4 basic compas directions. You feed them like a regular dipole antenna BUT you run each of the 4 feedlines into a remote switchbox.
In the switchbox are 4 magnetic relays, one for each of the dipoles. You run the common coax comming from your radio into a series of common relay contacts. Then all you do is to run the prower / voltage to the relays causing ONE or MORE to click down on the common contact(s) making the connection to the antenna.
THE ONLY THING to remember is that you have to use relays that have contact points that can take the power that you will be running thru the relay contacts.
The Next important thing to remember is that you do NOT transmit and change relays at the same time if you are pumping a lot of watts. In addition to the possibility of NOT having and antenna attached, if the wattage is high enough the contacts could have an arc that would eat up the contacts faster than you want to believe.
Signed,
That ELCO Guy |
Allagator
Advanced Member
Username: Allagator
Post Number: 516
Registered: 9-2002
| | Posted on Monday, November 29, 2004 - 6:54 pm: |
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hey ELCO where can you find one of them switches and remotes for a 4 dipole setup ???
Allagator !!
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Dindin
Intermediate Member
Username: Dindin
Post Number: 452
Registered: 2-2004
| | Posted on Monday, November 29, 2004 - 7:34 pm: |
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So would 3 gatorrods and a relay network be called a GatorScanner? |
Mikefromms
Intermediate Member
Username: Mikefromms
Post Number: 302
Registered: 6-2003
| | Posted on Monday, November 29, 2004 - 8:15 pm: |
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Hey, that gatorScanner sounds like a good idea. I do plan on building a loop. My first attempt failed because of the size of my frame. I'll get that thing right sometime. My antenna book tells me the loop will give you some "gain." Hey, gain from a wire.
mikefromms |
The ELCO guy (Unregistered Guest)
Unregistered guest
| | Posted on Monday, November 29, 2004 - 9:19 pm: |
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Evening G...
You might try your local electronics supply stores. What you are looking for is a relay that can handle a continuous voltage that you are planning on using, that the resistance of the points is not extremely high and one which has points that can take the wattage you will be applying.
If you do not have a local supplier you could try a google, or a Yahoo using the search word "Relay". Perhaps our good techs at coppers can sell you an appropriate relay.
If you want to see a project that uses this remote relay and contains a diagram of how to build such a relay check out the ARRL Antenna Book. Check the back in the Index for: Sloper sub topic 7-mhz sloper system.
Later
That Elco Guy |
The ELCO guy (Unregistered Guest)
Unregistered guest
| | Posted on Monday, November 29, 2004 - 9:19 pm: |
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Evening G...
You might try your local electronics supply stores. What you are looking for is a relay that can handle a continuous voltage that you are planning on using, that the resistance of the points is not extremely high and one which has points that can take the wattage you will be applying.
If you do not have a local supplier you could try a google, or a Yahoo using the search word "Relay". Perhaps our good techs at coppers can sell you an appropriate relay.
If you want to see a project that uses this remote relay and contains a diagram of how to build such a relay check out the ARRL Antenna Book. Check the back in the Index for: Sloper sub topic 7-mhz sloper system.
Later
That Elco Guy |
Allagator
Advanced Member
Username: Allagator
Post Number: 517
Registered: 9-2002
| | Posted on Monday, November 29, 2004 - 9:45 pm: |
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HUMM Dindin that would be a super scanner antenna !! LOL
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Kb9ojs
New member
Username: Kb9ojs
Post Number: 1
Registered: 1-2004
| | Posted on Friday, May 27, 2005 - 8:04 pm: |
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hey all,
I built many of these dipoles and everyone i sold them to loved them. I think it is the best antenna for the money if you like the 'roll your own' approach to antennas, since it cost about 5 dollars to make(no coax). Plus, it can be hidden in trees. When I have some time, I am gonna build one from 6061 aircraft aluminum and place it atop a 30' tower. 6061 is probably overkill, but i want an antenna that will have a long service life and one that will withstand the weather extremes we experience here in the midwest. I can't wait to chuck the A99 in the trash.
73's and good DX,
Junior, East Alton, IL |
Hotwire
Intermediate Member
Username: Hotwire
Post Number: 385
Registered: 1-2005
| | Posted on Saturday, May 28, 2005 - 11:05 am: |
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A99 in the trash? Why I never! |
Bruce
Senior Member
Username: Bruce
Post Number: 2733
Registered: 9-2003
| | Posted on Saturday, May 28, 2005 - 11:35 am: |
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Mail it to ..... |
Kb9ojs
New member
Username: Kb9ojs
Post Number: 2
Registered: 1-2004
| | Posted on Thursday, June 16, 2005 - 12:13 am: |
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I already have a local who wants the a99. I guess the only true beef I have with this antenna is that it is made from fiberglass. I always take mine down twice a year and put a coat of wax on it, but it will eventually rot. It is an ok antenna for what i use it for, but i enjoy the "overkill durability" factor of designing a 6061 aluminum vert. dipole.
73's everybody
kb9ojs "aka" Junior #483 East Alton, IL
And yes, if the guy who wants the antenna changes his mind, it will find a home at the garbage dump. |
