Need alittle help.Mounting several antenna's on a CVPI.

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Elighting
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Joined: Fri Feb 03, 2006 7:25 pm
Location: Chattanooga,TN/Bryant,AL

Need alittle help.Mounting several antenna's on a CVPI.

Post by Elighting » Sun Mar 05, 2006 11:59 pm

I will be receiving my 2000-01(PD selling the car's,unknownm what year I will receive) Crown Victoria Interceptor in the next week or so.I will be mounting a few antenna's on the trunk of the car. I will,at the very basic, have a VHF,CB and scanner antenna.The CB antenna will also be a NMO antenna,none of this magnet mount stuff.I may have a UHF antenna as well.

That makes a total of 3-4 antenna's.I want to mount all of these on the trunk of the car.How far should this array of antenna's be mounted apart?I know the ideal space is as far as the whips can touch(is 4 inches,then 4 inches,if 25 inches,then 25 inches apart).I want all the antenna's to be 5/8 waves.The scanner and such can be 1/4 if need be.

If anyone has pictures of a car with antenna's mounted like this or anything,send me a link to them.Any help would be appareciate.I'm not worried about the type of antenna's(maxrad vs. Antennex. etc.),just the mounting.Thank you.

Jordan,TFD,TCFD,VFD

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KF4SQB
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Post by KF4SQB » Mon Mar 06, 2006 11:11 am

Are you absolutely dead set on having them on the trunk? You would be much better off to put some on the trunk area, and some on the roof. If you absolutely had to have them all on the trunk, I would put no more than three there, one on either side ('beside' the trunk lid, if you get me) toward the rear, and one in the center of the trunk lid towards the front (preferably the scanner, as it doesn't radiate).
Brett Kitchens
KF4SQB

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Of all the things I've lost, it's my mind I miss the most.......

Elighting
Posts: 54
Joined: Fri Feb 03, 2006 7:25 pm
Location: Chattanooga,TN/Bryant,AL

Post by Elighting » Mon Mar 06, 2006 12:51 pm

KF4SQB wrote:Are you absolutely dead set on having them on the trunk? You would be much better off to put some on the trunk area, and some on the roof. If you absolutely had to have them all on the trunk, I would put no more than three there, one on either side ('beside' the trunk lid, if you get me) toward the rear, and one in the center of the trunk lid towards the front (preferably the scanner, as it doesn't radiate).
It's going to be a slick top and I don't want anything on the roof.I don't really want to mount anything on the rear fender,but will.The sheriff car's here have the antenna's on the roof(1/4 wave VHF)and it does not look good at all.Makes you look like a Teletubbie.I'm not going to be tranmiitting on more than 1 radio at a time.

The car that I'm getting,the PD puts the 800 Mhz antenna on the passenger rear fender,so I should have a coax there already.I was thinking I could put the scanner antenna there,since there will be a hole there already.The transmitting antenna's on the trunk.

Jordan,TFD,TCFD,VFD

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KF4SQB
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Post by KF4SQB » Tue Mar 07, 2006 12:48 am

My main reason for suggesting the scanner be the one in the middle of the trunk lid is the fact that it will not be radiating RF into the inside of the car. That is also the reason I suggested mounting the radio antennas at the rear of the fenders, so that they are as far from the interior of the car as possible, as well as being as far from each other as possible.

As for the car looking like a Tellitubbie, just paint it yellow and call it "La-La"! :o :lol:
Brett Kitchens
KF4SQB

kf4sqb "at" wetsnet "dot" com

Of all the things I've lost, it's my mind I miss the most.......

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wa2zdy
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Post by wa2zdy » Sun Mar 19, 2006 8:23 pm

The basic rule of thumb is that antennas be at least a quarter wave from anything else. On VHF high band, that's about 19 inches. On UHF it's six. CB is where you're going to introduce a problem for yourself.

An NMO baseloaded antenna for CB may be only 49 inches tall (a Larsen) but that doesn't change the fact that a quarter wave is 9 feet. So if you have it the suggested minimum from the other two antennas, they'll be happy but the CB antenna may be difficult to tune to a low SWR.

The quarter wave rule of thumb applies even if the antenna is actully larger - like a 5/8 on high band or a collinear on UHF. And you won't be putting a 5/8 on there for CB. That would be a tad large!

I think if I were you I'd dispense with the scanner. Being a wide band receiver, it will be too easy to nuke the front end being too close to the other transmitting antennas. Besides, four antennas on the trunk are just going to be too hamsexy. Sorry.

Good luck.
Chris Johnson
Wesley Chapel, Pasco County, Florida
http://www.wa2zdy.com
Member: S.P.A.R.
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