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UHF antenna question

Posted: Tue May 15, 2007 9:04 pm
by kurzo
im in the market for a new antenna and have a budget of around $150 and have seen some cheap ones on ebay, but whats the difference between them? i would think the higher dB the strong the antenna but why are the 6dB alot cheaper and shorter than a 4dB antenna?
cheers guys.

Posted: Tue May 15, 2007 9:33 pm
by zagan
dearest ant out of a shop has been $130.

That's one of those thick fibre glass ones, no idea what would be good or bad though.

Posted: Tue May 15, 2007 9:45 pm
by crispy
GME AE series are good.
The higher 6dB are better in long flat range but lack a bit in hilly country, where a 3dB is the opposite.
I have a AE4705 which is around 4dB and is a good allrounder but is rather large.
Something like the AE4012K2 would be a good option too

Posted: Tue May 15, 2007 9:56 pm
by Emo
Have a look at Prestige Communications website. They sell a great UHF antenna and fast delivery. Highly recommended.
RFI CD900 is about $90 and is indestructible.

http://www.prestigecom.net.au/default.a ... 8UHF+CB%29

Posted: Tue May 15, 2007 10:48 pm
by Goatse.AJ
Prestige are the go.

What sort of terrain are you gunna be using it in mostly?

If it's really hilly country, then don't go for anything much over 5 - 6 dBi.

For flat country, then go for the biggest sucker you can afford and mount on your vehicle.

Posted: Tue May 15, 2007 11:39 pm
by Jeeps
Emo wrote:Have a look at Prestige Communications website. They sell a great UHF antenna and fast delivery. Highly recommended.
RFI CD900 is about $90 and is indestructible.

http://www.prestigecom.net.au/default.a ... 8UHF+CB%29
I agree, this is the best antenna you can buy. GME $200+ antennas can't match it for signal quality & penetration. RFI is the leader in antennas.

Posted: Wed May 16, 2007 12:39 pm
by ceven
Jeeps wrote:
Emo wrote:Have a look at Prestige Communications website. They sell a great UHF antenna and fast delivery. Highly recommended.
RFI CD900 is about $90 and is indestructible.

http://www.prestigecom.net.au/default.a ... 8UHF+CB%29
I agree, this is the best antenna you can buy. GME $200+ antennas can't match it for signal quality & penetration. RFI is the leader in antennas.
I bought this antenna recently and its great, for $105 you also get a 3db antenna with it. Its further down on the page.

Posted: Wed May 16, 2007 5:25 pm
by kurzo
going to do some tours around vic, nsw and sa. and need a new one to neplace the pissy little 3dB i have, plus we go capming alot up the highland but arnt to far away from each other.

Posted: Wed May 16, 2007 5:47 pm
by T_Diesel
The most important aspect of any UHF antena is the quality of your ariel mount and the earth. If you have a bad earth, you can have the most expensive antena in the world but wont get stuff all reception with a bad or dodgey earth.

Posted: Wed May 16, 2007 6:44 pm
by crispy
unless its ground independant

Posted: Wed May 16, 2007 7:16 pm
by Jeeps
even ground independant antennas are ground dependant but it just depends on how dependant of their ground dependancy they are ;)

Posted: Thu May 17, 2007 9:24 am
by physh
Jeeps wrote:even ground independant antennas are ground dependant but it just depends on how dependant of their ground dependancy they are ;)
:? :? :?

Ohhhh-kay, I'm going to depend on your independent statement regarding ground independence to prove my independency... :roll:

Nah seriously - ground independent just means that it's already got a built-in way to guide the waves out of the antenna in the right plane (ie in the RFI900 elevated feed the actual foot of it is acting as the "ground plane" for it to push out from... http://www.rfindustries.com.au/rfiprodu ... age132.pdf )

Have a good read at http://www.rfindustries.com.au/rfitechT ... cs.htm#gpi

and http://www.mobileone.com.au/antennas/main477mhz.htm


It don't matter if you earth it or not, if it's ground-independent! :)


BUT... even if you don't earth it... They've gotta be good soldered connections right through too or you'll get crappy everything:
antenna - base - connector - cable - connector - radio - power connector - vehicle power

Bad connections in the radio freq path = big dB loss = crap transmission and reception.
Bad connections in power = can result in same due to voltage nasties, plus bad juju for your radio's longevity.

I've seen brilliant radios and brilliant antenna's installed crappily with dodgy connections and the result... = heap big crapola.

Posted: Thu May 17, 2007 12:09 pm
by kurzo
thanks guys i have a new one on order and i think i might repo the whole setup, conections and cables.
cheers guys.

Posted: Fri May 18, 2007 9:44 pm
by Buggarr
FLick Jaffa a pm. he's got Aerials he's gettin rid of and very cheap