| Author |
Message |
    
RCI 2990
| | Posted on Wednesday, October 29, 2003 - 3:04 pm: | 
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A 5/8 wave folded up or is it a 12 wave.. Also why does it talk better at a low heigt? |
rumblefish
| | Posted on Thursday, October 30, 2003 - 10:21 am: |
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I believe it's because the other antennas at a low height start to shoot the signal up more toward the sky. The top one is listed as a 5/8ths wave antenna, It's able to keep your signal along the ground even at lower heights |
mikefromms
| | Posted on Thursday, October 30, 2003 - 5:25 pm: |
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The thing really rocks even 9 feet off the ground. For under 30' they say it can't be beat.
mikefromms |
Dalowe
New member
Username: Dalowe
Post Number: 2
Registered: 3-2007
| | Posted on Saturday, March 17, 2007 - 2:51 pm: |
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It's a 5/8 wave. The AP accomplishes this feat not through coil loading, but though the unique (I believe the original was patented) design. It was my first base antenna, which I put up in '83. The path of electrical current through the antenna makes it a 5/8.
It talks as good at low height because it isn't bothered by the ground. If you could see the lobes produced by various antennas, you could see why. However, the higher the better, unless you mount it at the top of a hill with no trees or obstructions. |
Maxgain
New member
Username: Maxgain
Post Number: 2
Registered: 3-2007
| | Posted on Thursday, March 29, 2007 - 7:11 pm: |
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It is a shortened J pole. A Half wave . It has about 1.6 db of real gain.
You can not have a 5/8 wave antenna if your antenna is not physically a 5/8 in length. Loading coils do not make up for this.
If you could take a 5/8 wave antenna and bend it in half it is no longer a 5/8. Probably more like a 3/8 wave.
Don't be fooled! |
Tech833
Moderator
Username: Tech833
Post Number: 1635
Registered: 8-2002
| | Posted on Friday, March 30, 2007 - 1:29 pm: |
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Maxgain,
I believe you are fooled. The Astro Plane (Top One) is not a shortened J-pole as you suggest. It is an inverted 1/4 wave GP. The reason it is not affected by close proximity to ground is because the current node is at the physical top of the antenna and the voltage node is at the physical bottom. That is your dead giveaway.
Sure, it sorta 'looks' like a J-pole, but it obviously does not work like one. If it did, it would need to be mounted high above ground for good performance. |
Press_man
Junior Member
Username: Press_man
Post Number: 23
Registered: 5-2008
| | Posted on Monday, April 20, 2009 - 6:04 pm: |
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As explained to me back in the 70's. The Astro Plane or now Top One which I've used since the 70's is a folded 5/8 dipole. It, by virtue of design can work quit well at ground level and at 60'. I've had several omni antennas and have always returned to the Discone type antennas. Just my 2cent worth.
Sorry I've been off the forum so long, had to take care of several emergencies. Thought my oldest son was going to die and leave me as his
younger brother did. The oldest is better now!!! Thank GOD !!!!! |
