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Author Topic: BEST 10 thru 40 meter vertical with WARC bands?  (Read 511 times)
KC8CXZ
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Posts: 85




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« on: February 17, 2007, 11:20:21 PM »

I'd like to purchase a 'small footprint' multiband vertical antenna (10 thru 40 meters, with 12 and 17 meter WARC bands) for a small backyard lot with a fair number of good size trees.  I don't have room for long radials, so I was thinking Cushcraft or GAP, since they have fairly small counterpoises (radials?), and supposedly work well.  Can anyone make brand/model suggestions based on their positive experiences?  The antenna would be 'ground mounted' on a cement-sunk mast sticking out of the ground only about 6 to 8 feet.  

Thanks a lot!

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K3MOV
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Posts: 504




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« Reply #1 on: February 17, 2007, 11:55:24 PM »

I have been using the Hy Gain AV 640 (http://www.hy-gain.com/products.php?prodid=AV-640) for over five years.  It's mounted at 15'.  I have been extremely happy with its performance. See W8JI's comments below.

"When speaking of radials, I was talking about traditional Marconi antennas, but I do have an AV640 as a backup antenna myself.

I'm going to assume all AV640's are still like the early pre-production antenna I have. The small counterpoise is isolated from ground. There is a matching transformer and some decoupling inside the feed box. The decoupling is marginal on 40, and gets better as we go up in frequency.

There really isn't a need or a way to add radials. The 640 acts like an off center fed dipole on lower bands. Adding a ground system will mess it up since it depends on the "ground plane" being electrically small to reach resonance.

What this does is make the counterpoise to mast voltages very high (I measured several hundred volts between the counterpoise and ground on 40 meters with 1000 watts). The toroid used to decouple the feeder can't adequately choke off common mode currents on lower bands. Beside affecting SWR and pattern, feedline shield currents can lead to RF in
the shack.

In many cases, especially at low power, we get away with poor feed systems like this. We might never notice a problem. I noticed it here because my antenna was on a mast outside my shop and had the feeder coming right into the room . When I used my antenna RF got into everything, even the electronic ballasts in the shop lights. Of course noise from the light ballasts got back into the antenna. I increased feedline isolation near the feedpoint before the
cable reached the supporting mast with an additional high impedance common mode choke. Made the antenna useable in my situation. My lights with electronic ballasts don't shut off when I use it now.

73 Tom W8JI"
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HA6SST
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Posts: 110




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« Reply #2 on: February 18, 2007, 02:01:35 AM »

Get somewhere between twenty and twenty two feet of aluminum pole and put down as many ground wires you can. You will find it will tune all bands from 80 to 10 assuming you have a decent atu.

Make sure the pole sections are electrically bonded together.

HA6SST
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K3MOV
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Posts: 504




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« Reply #3 on: February 18, 2007, 02:20:44 AM »

"I don't have room for long radials".
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W5DXP
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Posts: 3546


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« Reply #4 on: February 18, 2007, 05:36:32 AM »

K3MOV wrote: "I don't have room for long radials".

The ground detunes radials. How long would your radials be if you did put them down?
--
73, Cecil, w5dxp.com
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73, Cecil, www.w5dxp.com
The purpose of an antenna tuner is to increase the current through the radiation resistance at the antenna to the maximum available magnitude resulting in a radiated power of I2(RRAD) from the antenna.
K9KEJ
Member

Posts: 21




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« Reply #5 on: February 18, 2007, 06:56:13 AM »

I've been using a 43-foot tall Zero Five Vert., and a 64 foot tall vert. I use both of them on 80-10 with an MFJ 989 tuner. Great signal reports!

Orrin
K9KEJ
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WY4J
Member

Posts: 110




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« Reply #6 on: February 18, 2007, 07:45:53 AM »

Check up the Gap Titan. Having been a die hard beam user I had a hard time downgrading to a vertical. I have owned mine for 10 years and I am still please with the results I get from this vertical.

I have mine mounted on the top section of the Rohn tower I used to have the beam mounted on. The section is hinged and attached to a boat pulley so tilting it down can be done in about 5 minutes. This is important in South Florida since a hurricane is always around the corner. I have mine guyed on three sides with thin Dacron rope.

This antenna requires no radials. It has a very low angle of radiation. Its coverage is 10-80 and my swr is around 1.5 on all bands.

I can't speak about the performance of the other verticals on the market but from my personal experience this setup works for me.
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N6AJR
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Posts: 9889




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« Reply #7 on: February 18, 2007, 10:50:12 AM »

I use a hustler 5btv ($159 ) as a backup to my beams, and a gap voyager for 40/80/160.
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N0IU
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Posts: 1248


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« Reply #8 on: February 18, 2007, 11:10:56 AM »

I have been using a Cushcraft R7 for about 15 years and I swear by it more than at it. I also used an R7000 for many years with good success. Neither of these are made any more and have been replaced by the R8.

Good news: These are very well made antennas.
Bad news: Relatively expensive: $540 (from AES)

You did say you wanted the best, right?

Scott N0IU
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W6OP
Member

Posts: 338




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« Reply #9 on: February 18, 2007, 05:14:08 PM »

A Hustler 5BTV or 6BTV works well and is easy to modify for 12 and 17 meters (see http://www.ad5th.com/).

Pete W6OP
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KG8JF
Member

Posts: 298




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« Reply #10 on: February 20, 2007, 02:40:43 AM »

I used a GAP EAGLE in Cleveland for several years and achieved DXCC and WAS with it.  It is just what you are looking for, very small footprint, no radials, will handle at least a KW, and it is lightweight.  Go for it!
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KG8JF
Member

Posts: 298




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« Reply #11 on: February 20, 2007, 02:42:01 AM »

I used a GAP EAGLE in Cleveland for several years and achieved DXCC and WAS with it.  It is just what you are looking for, very small footprint, no radials, will handle at least a KW, and it is lightweight.  Go for it!
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