Roachie replied:

Bo,
What are the brand/s and models of the 2 radios? We may be able to tell from that which is which as far as UHF and AM/27meg CB is concerned. They are both classed as "Citizen Band" as far as I know; meaning that Joe-Public (ie: citizen) can use either without any worries.
UHF has largely taken over from the older 27meg/AM technology, although latter does have it's advantages as far as distances able to be achieved using "skip"....but that's a bit hit & miss and you wouldn't want to be relying on it.

With 2 radios fitted, you'd need to have a separate antenna for each one (they are different types for each too.)

I would expect that the roof-mounted one would be for the UHF radio and even though it's only small, it probably has more "power" for transmit/receive that a larger aerial mounted on the bullbar. This is because a UHF antenna works better with a large "ground-plane" to assist send/receive messages. The roof acts like a satelite dish to gather signals and concentrate them on the antenna. I'd be leaving that one there.

If there is a base located on the bullbar, it maybe the location of the antenna for the 27meg CB. You'd need to get hold of a proper 27meg aerial and screw it on to see if it would work okay, but you may not get a response to any request for a radio check as no-one uses them much anymore.

Good luck

Cheers,

Roachie

The Banjo replied:

Indeed as Roachie says .....both are CB......one UHF as you say....the other HF probably (known as 27 meg, but still in the HF band). Make and model names will go a long way - expect many forumites will have them (or once did). As I see it - UHF is clear, popular, but comparatively 'local' in range. HF-CB is 'hashy', unpopular, but long range can be good (IF it has Side Band mode within - AM mode is really local))- the SB reach can be great, but not reliably so - much affected by HF "conditions". Don't chuck 'em out - with a bit of a tidy up, they might both be winners.

Truckster (Vic) replied:

HF is 27meg? na.

anyway search the archives for this, theres about 2 dozen threads on 27meg V UHF....

PeterWH replied:

Bo,
the tweo radios that you have got would be 27Mhz CB and 476Mhz UHF.
Usually the UHF antenna would be on th roof of your vehicle because it is mainly line of sight or thru a repeater....channels 1thru to 4 respectivelly,and the 27Mhz radio would have the base on the bull bar and a antenna to suit would cast anything from $20 upwards,depending on the typeof base and the cabling.
I would suggest that you getinto your local telephone book and look under two way radio specialists,contact them and find out what yiou require for both radios.
I have a motor home,which I put into it a UHF/27Mhz.
By the way another wayto check them out is to turn the squelch off with them both.
the UHF wont ahve any noise,but the 27 will makwe more racket than a car full of kids.
Good luck with it.

PeterWH
Rural NSW

Patroleum replied:

Simple Formula. The UHF set is the one you use and the AM set is in there as a spare wheel chock if you forgot to bring one with you.

Use the UHF

Steve

Bitsumishin - Mike A (WA) replied:

find a mate nearby with a UHF & try both radios, then you'll know which is which. Or if you are not embarrased easily, just broadcast on each and ask if anyone has a copy and what band are you using. Be prepared for some smart ar... replies though