29 replies to this topic

[stardude]

ello everyone

whos got a CB radio?

im getting one for christmas and was wondering what aeriels to people use? and how do they mount them?



get your pics up

adam

Edited by stardude, 16 December 2007 - 11:46 PM.

[Bevan]

I will shortly be getting a CB radio, although I dont know which one and what else I need to get. Should be a rite laugh on convoys!

[paulrockliffe]

I have one, I used a 4 foot aerial mounted to the bootlid, it makes the Mini look like a remote control car! Hilarious! Only problem is that I have NEVER heard anyone with my CB, I don't know if thats because my aerial is too small or because there's never been anyone within range. I keep meaning to buy a hand held CB as well, to make the system a bit more useful and so I can test.

I have just mounted my CB in my new car, but I haven't fitted an aerial yet as I don't know what the best way to do it is as the boot and everything else is made of plastic!

[MiNi FiZ]

i've got one ready to go in, it has a magnetic base i know you can get different one, the mount can be left outside and the aerial screws into it when you want to use it

[Southy]

You can get mounts which attach to the gutter rails and your aerial screws into the base and then you can run the cable through the boot or via an open rear window if fitted, this is how i fitted mine

[paulrockliffe]

http://www.4x4cb.com/

Problem I have is magnetic ones don't stick and I've got no roof gutter! Don't really want to attach it to my plastic boot either and they're better mounted above the roof line anyway. Was thinking about mounting a bracket to the rear subframe maybe, but haven't given it a lot of thoguht yet!

[stardude]

im getting mine from that website.

i think im going to get the magnetic mount, as i have a vinly roof so its not going to scratch the paint.


pics of aeriels?

[Southy]

I bought mine off a company called CDC truck accessories, they have a website but dont seem to be working, they are really good prices and the sevice is really good.

EDIT:They are situated at a transport cafe on the A14 near to Bury St Edmund's its called The Yorkies if your down that way at all

Edited by Southy, 17 December 2007 - 12:19 AM.

[Silicon Skum]

4x4cb.com are a great place - the owner knows what he's talking about, and very helpfull too.


For a CB antenna, you need it to be as big as possible, ie a full quater wavelength ( 104 inches / just under 9ft ) BUT that is not really a practical length to use (low bridges, trees, low hanging signs etc.). You would also need a mag mount the size of a bin lid to hold it down when driving.... Range will be in the region of about 8 - 10 + miles. Longer distances ARE possible (ie other countries depending on Solar storm activity - Sun spots / magnetic storms bring in distant signals on 27Mhz).

So a more practical size to use is about 4 to 5ft using an antenna that has a load coil - the antenna coils around at some point, commonly the base, so electrically it's still 104 inches long, but shorter in actual height. Range will be about 6 to 8 miles depending on the terrain.

The MINIMUM height antenna that can be used (and actually still WORK) is 3ft - BUT your maximum range you can transmit and RECEIVE is severly shorter than a bigger antenna - typically a max of about 1 - 3 miles in built up / city areas, and about 3 - 5MAX in open country. These are ONLY any use for nearby / close convoy use.


Don't bother with antennas that claim they are "half wavelength" but still only 5ft or so - electrically yeas they are, but the height is more important. It's just marketing. An actuall half wavelength antenna is about 18ft in length (height - as they are mounted vertically) and a full wavelength is 36ft.

Another myth is that modern antennas do not need to be "tuned" or "SWRed" - this is NOT correct - the truth is they are only fairly CLOSE to the expected settings for the frequency....... but that is assuming you have a similar size ground plane as their test bench uses. And you dont. Your "ground plane" is actually the body panels of the car - the roof being the best as it's higher and central. If the antenna is mounted to one side of the car, rather than central in the roof, the radio signal will be directed towards oposite side of the car (and so will the received signal) and anything behind the antenna will be very limited is range.

Get a SWR meter - you will need it or else youe could DAMAGE the CB (the final stage RF transistor will burn out) if the antenna is not set up correctly. In most cases this is a simple setup that takes less than 5mins, and usually just requires slackening of a small screw or allen key on the antenna and adjusting the height of the antenna whip by a couple of inches or less, until the SWR meter reads 1.5 or less (1.1 is ideal).


I have written all this before in more detail, have a search of the forum for the other CB topics for better information on antennas. I've put a few links to good antennas to use there aswell.



I have 3 mobile whip antennas I use on the mini - an 8ft Fire Stick 1/2 wavelength coil wound(this is an OLD antenna, but VERY good), a 4ft DV-27 (another very old antenna design) and a 3ft base loaded coil "stinger" type antenna (good for it's actual size, not much use for long distance!).

I will take pics of these antennas on the mini tomorow if you want, I only use a Mag-mount, which is slightly less efficient than a proper 'through panel' connector, but is still very good - and doesn't damage your roof! ALL my antennas are mounted central on the roof (I practice long distance communications - "DXing").

Actually, I might have to use the Bini, depending on if I have to move a lot of stuff out of the way of the Mini, which is in the garage for winter.

SS

[Dan]

Try telling all that to the so-called aerial installer who just last week put a new ridiculous 'digital bird cage' on the roof of my neighbours house, cunningly arranged so that its reflector is blocking a quarter of my aerial's reflector and is between two of my aerial's elements!

Sorry to jump in on your thread but I'm bitter and angry about loosing 1/2 my TV signal because some muppet can't put an aerial up properly. Anyhow back on track....

[Silicon Skum]

Try telling all that to the so-called aerial installer who just last week put a new ridiculous 'digital bird cage' on the roof of my neighbours house, cunningly arranged so that its reflector is blocking a quarter of my aerial's reflector and is between two of my aerial's elements!

Sorry to jump in on your thread but I'm bitter and angry about loosing 1/2 my TV signal because some muppet can't put an aerial up properly. Anyhow back on track....

I could tell you half a dozen ways to screw with the other antenna - but that's not really fair on the poor sods next door. Then again, you might not like them.

Funny thing is, your antenna is prolly causing the other antenna all sorts of trouble - the close proximity of your antenna will actually be detuning it slightly (you would get bad ghosting and poor signal on analogue, but only the occasional sound "chirp" and low level picture breakup on digital).

Would be terrible if you accidentally wired a high power signal booster backwards......dumping an overloaded signal straight into the other antenna..... Digital TV doesn't take too well to very high power levels.......


I think I would ask the neighbours to have it moved (at the installation guy's expense - his balls up!), and if they won't do that / play nice.........get a nice THICK metal pole mount, and have it installed right in front of the antenna section (the loop just in front of the reflector)......with a chunky antenna on top - natch. .

I could write a book: "100 ways to have fun with a Yagi" OR "How to make enemies and annoy people"

SS

[stardude]

fank you SS!!

i will probably be getting a 5' springer aerial

[Dom]

We all ready have a topic on CB radio's here

Your'll bound to find the info you need in 9 pages woth

[stardude]

thanks dom, i already had a look at that thread but didnt realy find much about aerials, or maybe im just blind lol

[miniturbonutter]

thanks dom, i already had a look at that thread but didnt realy find much about aerials, or maybe im just blind lol

I use a glass mounted CB aerial, it sticks to each side of the rear screen. Its only about 2 ft tall, so doesn't look out of place on the car. I admit it only reaches 3-5 miles, but for Mini convoys, it works great!!!