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two db-224A's on a repeater tower question

Jul 13th, 01:23

N0MZR

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
I recently passed by a repeater tower here in Iowa with two DB-224A separated between the tower with at least 1 wave length standoffs , oriented with a north/south pattern. We are wondering what are the advantages of this for repeater use. Will it double the gain of these 4 dipole , 2m antennas in a favored direction without changing the omni pattern that exists with one db-224A. Would it be worth our time to utilize such a setup on our repeater. Also, will losses increase? We have the antennas and will build a standoff to support these if there are positives to such a setup. Thanks for your input!
Jul 14th, 13:29

W1VT

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0

No, you can't get a higher gain antenna and still have a nice omni pattern by doing that. If you orient them so that you get an omni pattern, the gain goes back down to where you started. If you orient them for more gain in one direction, you no longer have an omni pattern. No way to get both, assuming that the net height, from the lowest antenna, to the top one, remains the same.

The only practical way of getting more omni gain is to stack the two vertically, doubling the net height of the antenna. This gives you more gain at the horizon, at the expense of a compressed vertical pattern. Usually this isn't a problem.

That arrangement may allow two different repeaters, run by different owners, on the same tower.

Zack Lau W1VT
ARRL Senior Lab Engineer.
Jul 14th, 21:57

N0MZR

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Thanks for the input, here in my local answers are hard to come by. I am glad we have the ARRL forum. 73 Everett n0mzr
Jul 14th, 21:57

N0MZR

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Thanks for the input, here in my locale answers are hard to come by. I am glad we have the ARRL forum. 73 Everett n0mzr

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