CB Antenna - Bullbar or Gutter Mount?

[Thomas-the-Terrano2]

arh, green oval issues so not a Nissan issue anyway.

[elty001]

I'm toying with the idea of mounting mine on the front wing.
I bought a second hand one as mine is rusted through but it has the mirror mount as its off an import.
the mirror is broke but the wing mount is still there so was going to adapt it to mount antenna on.
if it wont swr up as the mount is ally I will just ground it to the chassis.

[Lazy-Ferret]

Originally Posted by elty001

I'm toying with the idea of mounting mine on the front wing.
I bought a second hand one as mine is rusted through but it has the mirror mount as its off an import.
the mirror is broke but the wing mount is still there so was going to adapt it to mount antenna on.
if it wont swr up as the mount is ally I will just ground it to the chassis.

Ally wont be a problem, as long as it is electrically connected to wing and the wing is electrically grounded to the battery, it will be fine.. the only problem with ally is for people who want to use a Magmount.

When I did my RAE training many many many moons ago, I think I remember that Aluminium is actually one of the best electrical conductors, only surpassed by gold, but the problems with making good mechanical connections to it e.g., you can't solder or weld it, limits where it is used. If you think about it, most TV aerials are Ally.

[elty001]

ally is super conductive but I was told it was something to do with the ground plane.

[walshie]

As long as there's a good electrical contact to the wing the wing should act as a good groundplane. It'll only be a problem if the mount is electrically isolated from the wing itself.

[walshie]

Excuse my lack of knowledge of cb radio kit, are dipole versions of cb antennas not available? They would be far less susceptible to variation in mounting position?

[Lazy-Ferret]

There are, but I believe that there are 2 hangups..

Firstly, it would be illegal to run DiPole, but secondly, because of the wave length, on a car, you can not really get them far enough apart to be effective, where as on Lorries, they get them out on the end of the Wing Mirror frames, and can just get enough of a gap.

I believe a lot of Truckers run the DV27, 5/8wave aerial as Dipole, since the aerial is illegal anyway...

[walshie]

Ah ok, I think we have different meanings of the term dipole! Why r they illegal? And what freqs does cb work over?
I'm getting intrigued by the idea of cb in the car now! Lol

[Fez_uk]

Dipoles are not illegal...

It doesn't make sense to use one on a car anyway, As you will have to feed the coax halfway up the antenna.

Basically a CB antenna on a mag mount is just like a dipole, the car is the other half.

[Lazy-Ferret]

40 channels on the 27 MHz band and I am not sure, but there was also 20 channels on the 934 MHz band, both of which used FM, but not sure about the 934 now.

Re Dipole..

Antennas for 27 MHz CB

The following types of antenna are legal:

A single, vertical, omnidirectional monopole, the driven element of which does not exceed 6.95m in length or 55mm in diameter, including any loading coils and associated circuitry and casings, but excluding any plates, radial wires or rods designed to act as a ground plane or counterpoise, which are located at the physical base of the antenna; and

A single, vertical, omnidirectional dipole antenna not exceeding 5.55m in length.

Please note that the use of a loop, yagi or any type of beam antenna is prohibited.

[jims-terrano]

934was taken away by Ofcom several years ago, not sure but think it was sold off for mobile phones or summat.

[briggie]

934 mhz is illegal for cb now

[briggie]

i used to have a 934 set ..... think it was reftec ...... bluddie expensive radio at the time ..... the bonus was not many people could afford opne , so less idiots .