Aerial mounting location

[balloch]

I'm looking at installing a UHF in my Disco and I'm contemplating aerial mounting locations. I'm planning on mounting the aerial on the bullbar but there is already a mobile phone aerial on it. I have a bracket to fit to the bar and I have marked two spot on the bar where the bracket will fit without fouling the bonnet.

I would prefer to mount it where the blue line about 150-200mm away from the mobile aerial but I've read that having aerials close to each other can cause interference. I'd prefer it to be on the blue line as it's less in my line of sight but if I need the distance between the two I'll mount it on the red line.

https://www.aulro.com/afvb/images/imported/2009/06/1128.jpg

Is interference likely to be an issue or should I mount it on the red line?

Thanks for any input
Balloch

[Grover-98]

A mate of mine has a UHF aerial and mobile aerial about 100mm apart and he has never complained nor have i ever noticed any interference so 200mm should be safe as houses in my book. But let others share :)

James.

[Graeme]

I don't like looking through aerials so have them mounted near the windscreen at the edge of the bonnet/mudguards.

[gwebb]

I have my two ariels mounted each side of the bullbar and, apart from the first hour or so, straight after putting them on, have never noticed either when driving. You soon get used to them up the front and you look straight through them.
The main reason I put them there is because I did'nt want to make any holes in guards and placing them on the roof sill was not an option because I would not fit into my car port with them on.

[MickS]

Nice D2 mate...

[BigJon]

Mount it on the left (passenger) side.

Don't be surprised if the reception isn't very good when you are trying to talk to someone behind you. The structure of the vehicle will block a lot of the signal, particularly if the aerial isn't a great one.

I recently upgraded my UHF aerial for that very reason. The new one is long enough to clear the roof and my transmission / reception is much better.

[p38arover]

I have my two ariels mounted each side of the bullbar

:eek:

Two of these?

https://www.aulro.com/afvb/images/imported/2009/06/1098.jpg

[spudboy]

With UHF you want height. The higher the better. Get that by either having a short aerial mounted up on your gutter, or a much longer aerial on your bull bar.

Power is not transmitted from the top of the aerial but the bottom (think of a X-mas tree shape - that's the basic shape of the power radiation).

If you mount it on the bull bar, anyone behind you will only "see" the tip of the aerial above the roof-line, but hardly any power comes from the tip, so your reception will be greatly reduced.

Better to go for a short floppy on on a gutter mount. Doesn't look as cool, but you will notice the difference in the distance you can transmit.

[Sleepy]

Depends what you want to use it for.

If it just for convoy work (5 to 10km)use the bullbar. Ideally all antennas should be mounted well away from another but this isn't always possible.

If you want long distance (> 30km) comms (perhaps to reach a repeater that is in your area) you need to get a good antenna and mount it smack in the centre of the roof. Not always a good option for clearance.

Try the bullbar I think it would be fine for normal useage.

[It'sNotWorthComplaining!]

I done a bit of reading on various sites and they conclude that the Bull Bar is the Worst place any one can mount an aerial for maximum efficiency. Although all bull bar manufactures have a bracket to mount aerials.
You would probably be better off mounting it on a bracket attached to behind the spare wheel carrier and that would give you extra height to clear the roof and give better 360deg coverage. there have been some neat installations done this way. It depends on your needs.

[IceFyre]

I have a three piece extending tent pole u-bolted to the inside of the rear wheel carrier. There is a small bit of angle on top and the CDI-900 Aerial is mounted to that. It extends up beyond roof height for touring and can be dropped down for protection if necessary. Its wired through the back door and up to the roof mounted Icom 400 Pro. I also dislike having to look through an aerial and in addition this get the best positioning possible.

[Tusker]

Is the aerial you're contemplating ground plane dependent or independent? If dependent that limits your options.

Regards
Max P

[balloch]

Thanks for all the responses.

I'm only going to be using it for 4WD club trips for communications between vehicles so I don't need a huge range. I have had uhf aerials on bullbars on my previous 4wd's and found they worked well for what I used them for.

I'll go with mounting it on the passenger side.

Cheers
Balloch

EDIT: The aerial I have is a http://www.ryda.com.au/GME-AE4018K1-Heavy-Duty-Colinear-UHF-Antenna-p/ae4018k1.htm

[waynep]

The UHF transmits at 1 or 5 watts at 470MHz
Your mobile phone transmits a fraction of a watt at double that freq or higher.
Therefore if you mount your UHF in the blue spot it is POSSIBLE it could drop or interfere with any active phone calls when you transmit on the UHF. ( particularly if you are in poor mobile coverage area ).
What I'd do is a simple test : temporarily mount your UHF antenna at the blue spot and connect it to the UHF. Then initiate a phone call, and then transmit on HI power on your UHF. If the phone call stays connected and is not distorted, you should be OK.