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Best Repeater Antenna?


JoetheBugMan
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Repeaters require "high site" locations. High site means mountain top, highest building or tallest tower in the area. On mountain tops, lower gain antennas work better as they are more omnidirectional. As the gain goes up, the antenna pattern starts to resemble a donut more than a slightly squished ball. This increases the radiation pattern more to the horizon rather than filling gaps nearer the antenna. That said, an omni rather than a beam type antenna is what you are looking for. There are several designs that meet this requirement from vertical whip types to vertical poles with multiple folded dipole antennas attached. Your wallet will be a big deciding factor on which antenna you install.

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1 hour ago, JoetheBugMan said:

Any recommendations on what antenna to use with a repeater? 
   Thank you in advance. 

I have a buddy that wants to put up a Ham 70cm repeater, about the same as a GMRS one but a bit lower in frequency, when the site is ready. He spent over $300 on a USED multi-bay folded dipole antenna for it.

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I'm assuming that you are looking for somthing to put on a tower.  If you have the room for a 17-foot antenna, I suggest a Tram 1481.  I have one on my garage and I can hit a 2m HAM repeater that is 70 miles away.  When the conditions are JUST RIGHT, I can hit a GMRS repeater that is 40 miles away with a good bit of obstructing terrain in the middle.  8.3dbd of gain on VHF, 11.7dbd of gain on UHF.  NOTE:  That's dbd, not dbi like just about everyone else specs their antennas.  From dbi, subtract 2.1 to get to dbd.  So an antenna that boasts 2.1dbi = 0dbd, which is unity gain.

I have mine tuned so that my HAM bands are close to 1:1 in the middle of each band.  GMRS is up around 1.7:1, which is not great, but still usable.  At 2:1 SWR, about 10% of the power is being sent back to the radio, so my 50W is really somewhere between 40-45W (coax losses not withstanding).  The ground plane is adjustable and there is a good bit of adjustment remaining in the proper direction, so I'm sure that I could get the SWR lower in the GMRS band if I tried. 

If you do get one, get it from Staples.  Yes, the office supply store.  They have the best price around.

Finally, don't go cheap on the coax.

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