UHF Antenna's

I had similar requirements to you, and ended up purchasing the set listed below on the website link. Came with the two aerials (3db and 6db) which makes it easy to select the right aerial, and always means you have a spare in the car if something happens.
DSE Aerial

Gazza,

The cheapest ones are not very robust, but are functional.

The gain of the aerial can be important. Low gain (4.5 dB) doesn't have the range of higher gain aerials, but high gain (9 dB) tend to transmit largely in the "horizontal" plane so can be unsatisfactory in hilly country where the vehicle isn't always horizontal. Probably the best compromise is a 6 dB aerial.

I use a 6/9 dB aerial by GME and find that the 9 dB configuration is fragile (metal fatigue on corrugations) and in open country doesn't help much with range over the 6 dB.

Another factor to consider is whether a ground independent aerial is preferable. It's probably desirable if mounting on the bullbar, as it should perform a bit better than one that isn't independent.

My pick would be a 6 dB ground independent.

HTH

John

Hi Gazza,

Went through a similar thing a few years ago. I ended up moving the antenna to the roof and using a $13 quarter wave (short) flexible rubber aerial. Best reception I ever got, great in built up areas, very good over reasonable distance and pretty much indestructable. And... no one wants to pinch it.

Moving from the bull bar to the roof, I think, has made the major difference.

Cheers
Gerry

I live on the edge of the High Country & also do a lot of Outback travel, I ahve found that a 4.5db antenna is ideal & use a GME AE4705.

For Bullbar mounting, it MUST be the Ground Plane Independant type of antenna.

Just get the 9Db one and be done with it. Its not worth trying to improve a system that is not designed to work in hilly areas. So do the best for where the antennas are going to do the best - on the flats or when you are close.

The bull bar is one of the worst places you can mount the antenna. The best is in the middle of the roof. But we put racks up there and thats where it may get damaged from trees. So we end up back at the bull bar. Its all a compromise.

UHF won't bend around corners or up and over hills so we have to rely on reflections and refracted signals. Another compromise. Rain, hail, rees, shrubs and the ground condition will attenuate the signal again.

Practically speaking the range is as far as you can see plus a bit. It wont bend over the horizon except if the ground is a perfect conductor.

Not a pretty picture is it.

Thats why I say get a 9Db one and mount it as close to the center of mass of the car and as far as practical from any oither antenna or metalic object, where it is safe from damage and not sticking in pedestrians eyes and not in your direct line of sight.

Mostly practice soldering the antenna lead to the connector before doiung the final soldering. This is where most make mistakes. Just don't stick it in and think that is it. Its worth getting a good tech to do it and then best if he/she has done a soldering course. You have to make sure the impedance is not mucked up with a bad joint.

Phil

Other than reception transmission range there are a few other things to remember...

Some aerials are not recommended for Diesels.......yes its true. The vibration when idling will be enough to weaken the aerial and snap it off (generally at the base). These aerials are generally the single thick wire type without a spring base.

Having an aerial on the bull bar is not the best for transmission or reception. A ground independent aerial will help with that. The other advantage of the location is that as a driver you can see the aerial & see what its going to hit. This brings me to the last point...

A 4.5db aerial will be shorter than a 9db. The bigger the aerial the more likely is it will hit something....even your garage door!

One more thing, often the aerial will be a fixed aerial & lead combination, especially if its ground independent. If you need to replace the aerial, you will need to replace the lead too. It is possible to get a lead & base, fit a ground independent adapter & then the aerial of your choice (or perhaps just a ground independent aerial), that way if you need to change the aerial, is nice & easy.

Cheers

thanks very folks, much appreciate the input. it has helped a great deal..nothing like being armed with some background info before taking the plunge and regretting the decision due to lack of info

thx