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Author Topic: Antenna Location :. True or Fiction  (Read 10849 times)

AF6D

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Antenna Location :. True or Fiction
« on: May 23, 2014, 01:48:38 AM »

I have a DB224e that I am able to put up at thew 180 foot level of  commercial tower. I am told by those with an agenda, so it seems, that if I place the antenna on the south face where the person is standing in the attached image the antenna will be far enough away from the tower that the tower will be invisible to the antenna and omni directional coverage capable. This statement is made whether it is a DB224e or a Station Master.

I also have permission to mount the DB224e between the 160 and 180 foot level on the left side of the image. The cross arms are 20 feet apart. The DB223e is 23 feet in length.

I'd like to read some opinions on 1) the first statement that the tower will be invisible if spaced about 4 feet away from the main mass of the tower, and 2) mounting the antenna between the 160-180 foot levels, which is my preferences based on the fact that out in the free and clear there would be minimal interaction. The cross arms are also 20 feet long. 2" OD pipe on the top and bottom in an L configuration up/down. Attach DB224e. I have 1 5/8" hard line waiting wither direction I go. But I want omni directional coverage as much as possible. I do not pretend to know the answer and humbly ask for input.

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N1CX

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RE: Antenna Location :. True or Fiction
« Reply #1 on: May 24, 2014, 05:29:04 PM »

I think I'd opt to go off the sidearm with a db antenna like that. Set it for omni coverage and while I don't think you will have full omni coverage I think it should work ok. It's a compromise. I think the tower is going to give you some shading, how much is anyone's guess. The other thing you want to look at is what's in the near field of your antenna for frequencies and power...I'd be more concerned with this given that these are all vertical collinear antennas there already.

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AF6D

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RE: Antenna Location :. True or Fiction
« Reply #2 on: May 24, 2014, 07:28:23 PM »

I think we're on the same page, Scott. But why don't you think that the DB wouldn't achieve close to omni directional coverage? The image is a little misleading because the DB mounted to the cross arms would be done using 2" OD pipe out horizontally 5 feet and then a a 90° elbow going up or down.
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N1CX

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RE: Antenna Location :. True or Fiction
« Reply #3 on: May 25, 2014, 06:22:07 AM »

Because you have a very wide face of steel there that is going to act somewhat like a reflector. If it was top mounted it would be omni. Side mounted you will tend to get a more cardioid pattern.
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AF6D

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RE: Antenna Location :. True or Fiction
« Reply #4 on: May 25, 2014, 07:17:55 AM »

Exactly as I expected... and I wasn't willing to settle for the easy answer to shut me up.
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N1CX

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RE: Antenna Location :. True or Fiction
« Reply #5 on: May 25, 2014, 10:59:09 AM »

LOL I tell people you may not always like the answer I give you but it will be based on experience and science :)
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