Duplexer Question

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Prospect62
Posts: 69
Joined: Thu Nov 14, 2002 4:07 pm

Duplexer Question

Post by Prospect62 »

Hello to all. Here is what I'd like to do:

I have a GE MDX VHF (150) radio and a GE MDX 800 EDACS radio. Both are mobile radios. I have one NMO antenna mount on my truck and dont want to add another for fear of being labeled a wicked touch hole.

Can I get a multi-band antenna, add a duplexer and just run with it? I don't plan on transmitting on the EDACS radio much.

Will this setup work? What do I need to make it work, and does anyone have any suggestions? Thanks for the help, I know it's not all about Motorola for many of you guys!
thebigphish
Posts: 1477
Joined: Sat Nov 29, 2003 10:10 pm
What radios do you own?: AM/FM

Post by thebigphish »

Comtelco has a some unity gain Tri-band antennas that will fit the bill, one of our locals here did that (although much to my chagrin). You can do it, but i'm not a fan of combining / duplexing stuff like that. I'll always say that you can hide a second for better performance, than tri-banding stuff, especially if you're not using the middle of the range on the antenna (UHF)

Comtelco A11331A-z might fit the bill
akardam
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Joined: Thu Mar 04, 2004 10:53 am

Post by akardam »

Shouldn't be a problem. I actually have a setup that's kind of backwards from yours, in that I have a duplexer setup on my dual band radio going out to dedicated uniband antennas for each of the VHF/UHF side. Never had a problem with that setup.

Larsen makes a nice tri-band antenna, the NMO150/450/800. It's got 2 dBi of gain, and it's rated for up to 100w. I've got one on my scanner, and it works just peachy.

Finding a duplexer that does VHF/800 might be a bit of a challenge. The only thing I can find close to that is a unit Austin makes that is a commercial range VHF/UHF/800 triplexer, and it looks like it goes for around $150. The less expensive $80ish duplexer/triplexers you can find at places like HRO generally are setup for the amateur bands, and thus don't cover 800MHz.

If you're going to be mostly listening on 800, and fairly close to the towers, why not consider a black 1/4 wave 800 spike? Almost impossible to see, especially against a dark background, unless you're looking down at the top of the vehicle. I went from chrome antennas to black antennas a while back (except for the lowband whip), and unless you're close to my truck it doesn't look like they're there at all.
ASTROMODAT
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Joined: Tue Nov 05, 2002 12:32 am

Post by ASTROMODAT »

Radial/Larsen has several tri band antennas and tri port duplexers that should work just fine.

larry
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Prospect62
Posts: 69
Joined: Thu Nov 14, 2002 4:07 pm

Plex

Post by Prospect62 »

Thank you for the input fellas. I will try Radial/Larsen and if that doesn't work out I suppose I'll try a seperate, less noticable antenna for the 800.
Jim1348
Posts: 542
Joined: Sun Aug 15, 2004 7:52 am

Larsen NMO150/450/800

Post by Jim1348 »

I am now in the market for a tri-band antenna. How well do these work out performance wise?
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007
Posts: 1546
Joined: Sat Nov 23, 2002 5:22 am
What radios do you own?: W7 FPP lowband MaraTrac w/AES

Post by 007 »

I've got the MaxRad tri-band V/U/800 antenna, and it works great. It's been used with both Comet and Larsen triplexers with no problems.
Do not make Sig angry...he'll just keep ringing the bell.
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