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Antenna ideas

Posted: Mon Oct 31, 2005 3:51 pm
by bellersley
I'm looking at doing an install on an older Buick. I'm going to need two VHF antennas, one 800 and one UHF. I was thinking of putting a 5/8 wave VHF on the trunk, a VHF 1/4 wave on the roof and an 800 window-mount. I'm at a loss for a UHF though. Any ideas?

Posted: Tue Nov 01, 2005 12:16 am
by DaBigBR
Nub style on the roof or trunk, or trunk lip?

Posted: Tue Nov 01, 2005 12:20 am
by Conundrum
these are just an idea, not sure how good it would be though,

2 lip mount VHF antennas on either side of the trunk, UHF on the center of the trunk, and 800MHz Glass mount on the window.
or
2 lip mount VHF antennas on either side of the trunk, 800MHz OR UHF on the center of the trunk, and 800MHz OR UHF on the roof.

Posted: Tue Nov 01, 2005 12:48 am
by bellersley
Well, for UHF I was thinking a low-profile job on the roof, much like the "pie plate" style that Antennas Plus or Larsen make. I was also thinking a Phantom antenna on the trunk lip right up near the front (window end) of the trunk. UHF wouldn't be used very often anyway so I suppose even a mag-mount might work.

Posted: Tue Nov 01, 2005 5:51 am
by va3wxm
How about the 2 VHF's on the trunk, and the UHF and 800 on the roof (like PRPD use on their cruisers)?

If you're averse to drilling holes, Larsen makes a very good glass mount for UHF (KG-4x0).

I've personally seen the light and will no longer use mag or lip mounts for my antennas. :)

Posted: Tue Nov 01, 2005 6:20 am
by Sam
How about a VHF/UHF dual-band in place of the 1/4-wave VHF? Maxrad and Comtelco both make 18" models that are 1/4-wave on VHF and give you about 3dB gain on UHF. (I have one of each and I love them.)

You'd need a diplexer to use the single antenna on two different radios, but they're not too expensive. If you're looking to reduce the number of antennas or holes, this might be a way to go.

--
http://www.maxrad.com/cgi/maxrad_produc ... alog=10003
http://www.comtelcoantennas.com/PDF%20D ... /A1131.pdf

links added

For a dual band aerial............

Posted: Wed Nov 02, 2005 5:08 am
by M3SGC
Hi all I appreciate that I am "over the pond" but I bought a dual band amateur aerial from this guy http://www.garex.co.uk/aerials/whips.htm
I use the "Hinge Lug" centre loaded model and it is jolly good. As explained in the text it is a well made & functional aerial, good value for money!

Posted: Wed Nov 02, 2005 5:46 am
by grinthock
Depending on your needs / wants I don't think that Lip Mounts are the best option, NMO's give you a really nice ground plane. All my stuff was lined up in the center

I has basically your setup in my Impala, worked great.

Dual Band VHF/UHF SBB-5 on trunk (dual band radio but you could use a duplexer)

800mhz NMO on trunk and 1/4 Wave VHF on Roof (Which works awesome!)


My preferred option, and what I would have done had I not sold the vehicle would have been

5/8 Wave VHF on the trunk, UHF of some kind on trunk probably 5/8, 800mhz glass mount, and 1/4 wave VHF on rooftop.

Antenna stuff...

Posted: Wed Nov 02, 2005 9:44 am
by Tom in D.C.
Remember if you're considering one of the Antenex Phantom or similar "funny" antennas that the transmit bandwidth can be very limited. These units are fine at their resonant frequency but the SWR goes out of sight usually when you move up or down by 1 mHz. My experience has been with the VHF unit, but I also run a Phantom now on 900 mHz where it does fine, though the transmit "swing" around 902 mHz is less than 1 mHz; it seems to receive fine on 927 mHz as well.

Re: Antenna stuff...

Posted: Wed Nov 02, 2005 10:14 am
by JohnWayne
Tom in D.C. wrote:Remember if you're considering one of the Antenex Phantom or similar "funny" antennas that the transmit bandwidth can be very limited. These units are fine at their resonant frequency but the SWR goes out of sight usually when you move up or down by 1 mHz. My experience has been with the VHF unit, but I also run a Phantom now on 900 mHz where it does fine, though the transmit "swing" around 902 mHz is less than 1 mHz; it seems to receive fine on 927 mHz as well.
This was true of the older VHF Phantoms which only had a 1.5Mhz bandwidth. However, the new VHF Phantom Elites have a 5MHz bandwidth. Both the original Phantoms and the new Phantom Elites have a >20MHz bandwidth on UHF, and a >70MHz bandwidth on 700/800/900/2400MHz.

Jeff

Posted: Wed Nov 02, 2005 10:56 pm
by bellersley
I do NOT want a VHF phantom, they look really bad (IMHO). I think what I'm going to do is have a Sinclair Excalsior VHF on the trunk (the one that's 3 feet long), then put a Sinclair Excalsior VHF on the roof (1/4 wave), an on-glass 800MHz then a UHF antenna on the roof as well. For the UHF I was thinking either the Phantom or the Larsen low-profile style. Not sure which yet. I don't want to put two on the trunk as there's already an NMO mount, but it's right in the middle of the trunk so I can't put two properly spaced antennas on the trunk, so I'm going to just leave it the way it is.

Thanks for the advice all!