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Dual band antenna system?

Posted: Mon Oct 23, 2006 7:56 am
by rwo978
I know they make dual band antennas.......... but, do they make anything for commercial bands and do they make anything that would work in my situation?

Have a dual band radio setup, one control head, two separate deck (UHF and VHF). Both decks have their own power cords and own antenna connections. However, only one band recieves at a time, similar to any other scanning radio. Does something exist that I could run 2 antenna wires to from each deck, some sort of automatic switch that detacts which bands is being used, which then sends/recieves the signal via 1 antenna wire to the dual band antenna? I'm looking to save space/roof holes, as I already have a UHF, a VHF ham, and a VHF scanner and don't want to add another VHF commercial band unless last resort.

I already tried an on-the-glass scanner ant that I had from my last vehicle and the reception is crap, so I want that on the roof again. Help?

Posted: Mon Oct 23, 2006 9:06 am
by RESCUE161
They make diplexers that would do what you want, but I have no idea how well they work.

Posted: Mon Oct 23, 2006 9:52 am
by 440roadrunner
The statement

UHF and VHF

Does not tell us what band(s) you are on

Posted: Mon Oct 23, 2006 1:02 pm
by lieut25
Im running a vhf and a uhf cdm 1250 into a opek model DU-500 vhf/uhf duplexer along with a antennax dual band antenna. My swr's are fine and im only loosing about 5 watts transmit on the vhf radio.

Posted: Mon Oct 23, 2006 4:44 pm
by rwo978
144 to 160
444 to 470

Posted: Mon Oct 23, 2006 4:55 pm
by 440roadrunner
With all due respect, I don't think there's ANY antenna with that wide bandwidth.

Maybe a quarter wave whip, cut somewhere in the middle, and made out of VERY thick material You can operate it on the third harmonic on UHF.

The kind of bandwidth you are asking for is more like a discone.

Posted: Mon Oct 23, 2006 6:10 pm
by bellersley
The Larsem NMO270, while being an amateur antenna, is just as well built as any commercial antenna. You could probably tune it down to what you need.

Larsen

Posted: Tue Oct 24, 2006 4:27 am
by 1 Adam 12
Look here :
[url]http://www.radialllarsen.com/docfiles/A ... VHFUHF.pdf [url]

And they also make a splitter, which allows for exactly what you wanted 1 antenna to a diplexer to a UHF & VHF rig. A The antenna performance, should be acceptable depending on which model you choose. They do make custom set-upd... but its $$.

Posted: Tue Oct 24, 2006 9:54 am
by Batwings21
Sti-co makes undercover antenna's that are dual that should work for you. The DEA uses them and The IRS had them around here for many years. They are probably several hundred dollars though. They had a Cellular look alike antenna with a engineered cable that ran to a diplexer.

Posted: Tue Oct 24, 2006 11:45 am
by N4DES
Those Sti-co Antennas in the VHF band aren't very broad though.
Using the Sti-co tuner the best I have ever seen for a 2:1 VSWR was no
more than 1.5 MHz and would be short as to what the OP want's, but what he want's isn't really available anyway.