Diamond D-130J Tower Mount question

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Pyr8

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I have a 35 foot tower on the side of my house for my 4G high speed internet connection. As you can see in the photo, it uses a directional patch antenna.

The question is, would there be an issue mounting my D-130J discone directly below the patch antenna without the use of a side arm mount? The mounts that come with antenna are "C" type clamps that will have the main mast of the antenna sitting 2 inches from the mast of the tower.

In an ideal world the discone would be mounted to the very top of the tower mast, but I need the extra height for the patch antenna.

I'm wondering if mounting the discone parallel to the tower mast will be an issue for reception?

See photo for details (I added a "discone" in paint for a visual explanation) !

 

popnokick

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There shouldn't be any interaction between the antennas. However, the discone's longest elements may be affected by having the metal tower mast close to the discone. Pattern distortion, reflection, absorption, etc. It might be difficult but assuming the directional patch antenna has a good LOS to the other end of the link, you could put the discone at the top of the mast and the directional patch just below it. That way the discone would be in the clear WRT parasitic metal objects in close proximity.
 
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mmckenna

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Having an antenna that close to a piece of metal is going to make it slightly directional. For monitoring this isn't going to have a huge effect, but if you ever transmit with it, issues are likely.

There are two suggestions I'd make:
1. Move the patch antenna down enough to squeeze the discone on top. It shouldn't take much, maybe a few inches at most. This would likely not affect the patch antenna, and will improve how the discone works.
2. Use standoff brackets to keep the antenna away from the mast/tower.
 

Pyr8

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Having an antenna that close to a piece of metal is going to make it slightly directional. For monitoring this isn't going to have a huge effect, but if you ever transmit with it, issues are likely.

There are two suggestions I'd make:
1. Move the patch antenna down enough to squeeze the discone on top. It shouldn't take much, maybe a few inches at most. This would likely not affect the patch antenna, and will improve how the discone works.
2. Use standoff brackets to keep the antenna away from the mast/tower.
I was looking at using a "side arm mount", but the run $200, not worth the investment IMO!
 

mmckenna

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I was looking at using a "side arm mount", but the run $200, not worth the investment IMO!
Yeah, I think you are correct, not worth the investment. It would probably not hurt your link antenna to drop it down enough to fit the discone up top. That is the ideal situation.

I'd really be surprised if lowering your data link antenna a few inches would cause it to stop working. If the link budget on the system is that close to the edge, you'd probably see a lot more failures on your link.
 

koz303

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I know i late on this, How about a longer mast so your patch antenna will be the same height, then mount the D130J on the top of the mast. Just a thought.
 
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