| Deciding where to put the aerial...
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As a general rule, the higher up the aerial is mounted, the better it will work.
You should have the aerial in a position where there is nothing too close to it, as close proximity of other objects will have an effect on the SWR reading - more on SWR later.
Most mounts will require a hole to be drilled somewhere on the vehicle, although magnetic mounts will stick to steel roofs and bonnets.
With "through hole" mounting, you also have the advantages of having the connection & cables inside the vehicle, away from any branches that might snag, and avoiding the hassle of bringing the cable back into the passenger compartment.
If you decide to mount the aerial so the cable is outside the vehicle - use tie-wraps with short spacings to make sure you don't rip the cable off with a passing branch. If you're talking to someone very close, you might not immediately notice, but damage will be done to the set.
You have a number of places to fit an aerial on a 4x4 vehicle...
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1 Through the roof : You can drill a hole in the roof to mount an aerial. Use a dome or stud mount for this. If fitting into a Land / Range Rover with an aluminium roof, care must be taken to make a good earth connection. You may need to add a strengthening plate for very large aerials.
(Pictured here is a full-size Springer on a dome mount on the roof of a Range Rover Classic)
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2 Rear of the vehicle : This is often the best place to mount an aerial, as you can get the mount high up on the back of the vehicle, but with the aerial mount just below the roof line. This means the aerial will work well - being high, and give it some protection from branches.
Pictured here is a full-size Springer, mounted onto the back of a Land Rover 90, using a PSM-1 mount.
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3 Roof rack : If you have a roof rack fitted, this can be a good place to have the aerial. Our mirror mounts will clamp around the bars of a roof rack - you will need to file a small area back to shiny metal (i.e past galvanised layer, or paint) to make a good earth connection. This doesn't need to be a large area, just so that a part of the mount is making good metal-to-metal contact. The rack itself will act as a "ground plane" or earth - see our other pages.
(Pictured here is a Sirio Hi-Power 4000 on a PL dome mount, bolted to a roofrack with a standard "mirror mount")
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4 Gutter mount : Gutter mounts work well on steel roofed vehicles although they are on the side of the vehicle so they can be prone to damage from passing branches and their cables can easily get snagged on things. They are held on by two screws that tighten down into the trough of the gutter - they need to make metal-to-metal contact.
With aluminium vehicles you will need to protect this earth connection. The normal way to prevent alluminium from oxidising is to use a zinc based paint like "Red Oxide" or similar rust inhibiting paints. Obviously, red paint on the outside of the car is less than ideal, so a spray-on (aerosol) plastic sealant will do the trick and not be so visible to the eye.
(Pictured here is a Sirio Hi-Power 4000 on a Sirio KF gutter mount)
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5 Front bumper / bullbar : On the top of a bullbar is a common place for mounting an aerial - especially in Australia, in fact many ARB products have aerial mounting plates designed in. We have a mount that is suitable for most round bullbars upto 2.25 inch diameter
Do bear in mind that theft from this position might be a problem. Mounting on a standard bumper can work, although the amount of metal around the aerial can cause tuning and performance problems.
Also, having a flexible aerial down this low can be dangerous - getting whipped in the face is an off-road site marshals' nightmare... it has happened!
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6 Front wing : You can put an aerial on the front wing, as long as it is not too close to the windscreen and rest of the body. At least 2 feet away is best. Again, a dome mount is ideal.
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7 Rollcage : If you have a roll-cage fitted, this is another good place for an aerial - some already have lamp brackets on them, or if you can fabricate a small metal plate and weld it on or use exhaust clamps to secure it. Never try to drill through the rollcage to fit a mount - this will destroy it's structural strength.
We now carry a mount that is suitable for most round rollcages upto 2.25 inches diameter
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