Repeater antenna suggestions

[WQOC472]

hello all,

I know this is a amateur radio antenna forum. However i am putting up a repeater on GMRS. (once i get my ham license i will likely switch it to a 70cm repeater) I was wondering if anyone had any suggestions on antennas. I have a VXR-7000 repeater with a motorola 4 cavity duplexer. I am using Andrew LDF4-50A heliax hardline.

I have been looking at a DB411, Due to its 9db gain.

Any suggestions would be greatly appreicated!


Thanks!

 

[willgrah]

Coverage Prediction You will have to quick register but this is a great way to get an idea of potential coverage. You can change the wattage, height and antenna gain. You may find that you need less gain. Good luck, wish you were closer I could use another repeater in the neighborhood. Bill WQOV721

 

[zz0468]

The DB411 is a good choice. Telewave makes some similar folded dipole types. I will make a specific recommendation that you not consider Telewave fiberglass collinear antennas, however.

Depending on the site conditions, 9db might be excessive. Unless you get an expensive antenna with null fill, they have a lot of holes in the vertical pattern above and below the main lobe.

 

[n8zcc]

I'll second the folded dipole. Used one on a 2 meter repeater for many years with out problems. Be careful about the db rating, is that dbd or dbi? Also the gain will vary depending on the orientation of each dipole. I believe that gain rating is is 9 dbd if all four dipoles are pointing the same direction but this will not provide a omni-direction pattern.

 

[kayn1n32008]

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If looking at folded dipole array antennas, Also look at Bluewave and Sinclair Radio Labs. I have a db something and it looks cheap and light duty. Bluewave and Sinclair make models that have all the phasing and cableing enclosed inside the elements and mast the dipoles are mounted on

 

[dksac2]

One metal folded diapole at about 3 DB gain will work fantastic, they are metal and will take the weather that is usually at mountian tops. They work and hold up.
If you have the height, you don't need a whole lot of gain, you need your signal to go down as well as out in as good of an equil pattern as you can get it to go.
High gain will go over a good part of the bottom of the mountain and usually have some nasty lobes.

John

 

[kayn1n32008]

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A single folded diploe is 0dbd or unity, you need 2 for 3dbd gain.