Base dual-band ham antenna

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K4RXR
Posts: 52
Joined: Thu Feb 03, 2005 9:07 am

Base dual-band ham antenna

Post by K4RXR »

The county where I live is developing plans for a new Emergency Operations Center. I suggested to the EMA Director that the new EOC should have provisions for amateur radio. He contacted the "owner" of the building where the new EOC is going and we have an agreement in principle to mount an antenna on their tower and run a coax into the EOC.

The antenna will be going up at around 30-40 feet AGL. We'll need access to 2m and 440 repeaters in at least a 20-mile radius. It'd be nice to have simplex coverage to mobiles in a 20-mile radius, but that may be too much to ask given the height of the antenna.

What antenna should I propose for this application?

Thanks!

Bob...
440roadrunner
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Post by 440roadrunner »

Hustler G6 series
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apco25
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What radios do you own?: APX / Astro 25 / Harris

Post by apco25 »

Feed it with some 1/2 heliax or bigger and it will do very nicely.
"Some men just don't know their limitations"
techie
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Post by techie »

I don't know if you have any 6m or 220 or 1296 activity in your area, but you might want to consider a tri-band antenna.

If you are doing an EOC, you probably want at least two antennas. You never know when you are going to need packet, or a simplex channel in addition to whatever else you are running.

Also, see if you can get some spare coax lines to the roof for your use, in the event you need to add some temporary antennas.
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spareparts
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Re: Base dual-band ham antenna

Post by spareparts »

K4RXR wrote:The county where I live is developing plans for a new Emergency Operations Center. I suggested to the EMA Director that the new EOC should have provisions for amateur radio. He contacted the "owner" of the building where the new EOC is going and we have an agreement in principle to mount an antenna on their tower and run a coax into the EOC.
Hendricks County, Indiana?? Ask how much tower (wind) load you are being "given". Once you know that, you can determine the antenna system. As noted uptopic, multiple antenna's work better then a single multiband unit

BTW, A good guide for any communications facility construction is the Motorola R56 site manual. NFPA 1221 is a standard for this type pf facility as well.
SlimBob
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Joined: Thu Dec 18, 2003 11:38 am

Post by SlimBob »

I'd say a DB-224 or SuperStationMaster with an upper sway mount. If you're only going to be able to climb once....

Alternatively, the next best antenna for *any* VHF/UHF band would be a discone, probably a STI-CO discone simply because it's a rugged antenna. A discone can be used for almost any band inside of it's operating range, provided that you feed it with good coax and that it retains an effective shape for the higher bands.
440roadrunner
Posts: 236
Joined: Mon Aug 16, 2004 3:47 pm

Post by 440roadrunner »

I'd say a DB-224 or SuperStationMaster

Neither one of those is dual band, unless you want to blow the bucks on 2 of them and use a dual band coupler.
SlimBob
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Joined: Thu Dec 18, 2003 11:38 am

Post by SlimBob »

440roadrunner wrote:
I'd say a DB-224 or SuperStationMaster

Neither one of those is dual band, unless you want to blow the bucks on 2 of them and use a dual band coupler.
Ok, fine. DB-314. :-p
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