Mud-club
Vehicle & Technical => Discovery => Topic started by: chris_harvey on April 25, 2010, 17:43:33
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i am gettin a cb radio as the club ive joined the majority have them and have constant comms on green lane days and stuff anyway the problem ive got is i dnt know what the best antenna mount or even what 1 is right for me disco 1 ??? any help would be gr8 thanks in advance
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A large mag mount with a springer/stinger type aerial will get you started without drilling any holes. You can get gutter mounts or body mounts but you have to pick the aerial carefully then, as the number of places where you can put a body mount and still get decent performance is limited.
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As he said above ^^^ the Mag mount will do for a start. But the best is a hole in the roof with a good sealed mount.
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Hi Devon
Remember what you want the CB for. I assume it is to keep in touch with those in the convoy or near by. You don't need long range.
I just use the mini springer on a mag mount. It does all I what of it.
No point spending lots of £££ unless you are trying to get every last inch of range out of your set. (and a long aerial will only get bent or broken under trees when laning)
Ed
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I got fed up with the mag mount being knocked off by low branches and changed to a gutter mount above the back door.
Gav
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I went for 2 truck type mirror mounts from Thunderpole on my roofrack, with the "trucker HD" ariel its a great setup for laning
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Ive got a mount that sits between the spare wheel and rear door mount, very strong and wit a mini sporinger on its no soo tall that it catches the trees etc. I got mine from Ebay for about £17.
Brian
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I got fed up with the mag mount being knocked off by low branches and changed to a gutter mount above the back door.
Gav
Snap! except mines a 6ft orbitor mounted to a stainless steel gutter mount fitted to the right of the rear door, the mount has a adjuster knob on it that allows me to tilt the aerial towards the centre of the car if the lanes are very overgrown.
For greenlaning Antenna position really is irrelevant just so long as you can get a decent Swr reading. Absolutely anywhere will suffice.
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Range is merely the result of what SWR and power the rig is putting out. It isn't the fact of saying that i will put up with a poor SWR as i don't need it to be any better to talk to my mates.
A good SWR will mean for close convoy work you will be able to comfortably talk to everyone and should the distance increase you won't spend time swearing to yourself, as no one can hear you and the CB is as much use as a chocolate fireguard.
And yes the 'Orbitor' in the long or the mini variety is the choice for laning. (i have a mini on 90% of the time) But i do keep a meteor in the back and should i want a perfect SWR it is a 30second change over to swap Aeriel's. As for range i don't know as i haven't tested it. The worlds my oyster if the skip is right. ;)
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SWR has nothing to do with how well an antenna transmits or performs, a good SWR just means the antenna load is more closely matched to that of the radio, in this case ~50ohm.
Just to highlight that, a non inductive resistive load of 50ohm (i.e dummy load) with give a near perfect SWR reading yet is a very poor at resonating RF.
My suggestion for a greenlaning/convoy antenna is nothing more than a RF leaky (unshielded) dummy load capable of safely dissipating the heat from ~5watts of power. This can be put on the end of a length of coax and hung/hooked/stuck on suitable location inside the vehicle. The range will vary but should be satisfactory for a few hundred feet line of sight. No worrying about routing cable to outside of vehicle, no worries about tuning, no worries about trees, no worries about mounting and earthing brackets and mounts.
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SWR has nothing to do with how well an antenna transmits or performs, a good SWR just means the antenna load is more closely matched to that of the radio, in this case ~50ohm.
Just to highlight that, a non inductive resistive load of 50ohm (i.e dummy load) with give a near perfect SWR reading yet is a very poor at resonating RF.
My suggestion for a greenlaning/convoy antenna is nothing more than a RF leaky (unshielded) dummy load capable of safely dissipating the heat from ~5watts of power. This can be put on the end of a length of coax and hung/hooked/stuck on suitable location inside the vehicle. The range will vary but should be satisfactory for a few hundred feet line of sight. No worrying about routing cable to outside of vehicle, no worries about tuning, no worries about trees, no worries about mounting and earthing brackets and mounts.
well, that went right over my head!! lol i use a k40 whip antenna on a good mag mount. its pretty long but the good mag mount means it needs a hefty clout to knock it over.
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Think about a hand held CB too :-k
That's what I use with a mag-mounted antenna. With the hand held I can just unplug it from the antenna and leave the vehicle with it, in case I need to walk a route before etc :D
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I never had any trouble with the mag mount being knocked off by trees, even with a full size springer on top and driving trails where the greenery was brushing over the roof. Mine came from Maplin and is about 6" across with a pretty powerful magnet. I know when I took it off to swap to a body mount on the back door (wish I hadn't, it was much better on the roof but I didn't know much about CB then) it required a fair bit of finger strength to persuade the mag mount to let go! :lol:
I am considering a centre-loaded aerial in an effort to improve the performance with my current mount, basically I need to get the coil up above roof level. The 9' whip aerial works fine on this mount but the rigid lower section is just slightly too long for use if trees are likely.
Anyone know if fitting a back door ladder and then bolting a mirror mount to it would work well or be desirable? I suspect it'd be a pain if you ever wanted to use the ladder to get onto a roof rack.
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I never had any trouble with the mag mount being knocked off by trees, even with a full size springer on top and driving trails where the greenery was brushing over the roof. Mine came from Maplin and is about 6" across with a pretty powerful magnet. I know when I took it off to swap to a body mount on the back door (wish I hadn't, it was much better on the roof but I didn't know much about CB then) it required a fair bit of finger strength to persuade the mag mount to let go! :lol:
I am considering a centre-loaded aerial in an effort to improve the performance with my current mount, basically I need to get the coil up above roof level. The 9' whip aerial works fine on this mount but the rigid lower section is just slightly too long for use if trees are likely.
Anyone know if fitting a back door ladder and then bolting a mirror mount to it would work well or be desirable? I suspect it'd be a pain if you ever wanted to use the ladder to get onto a roof rack.
Easier to get a mount like mine. You take the spare wheel off the back door and slide the mount over the stude that the wheel goes on Then put the spare wheel back on the studes and tighten the nuts. Then put your antenna mount to the aother end of the newly fitted bracket.
I got mine from ebay for £17 ish just had a quick scan and cant see any on at the moment but they do come up often and im sure there are other places that sell them. You can get them for all sorts of 4x4s.
Brian
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SWR has nothing to do with how well an antenna transmits or performs, a good SWR just means the antenna load is more closely matched to that of the radio, in this case ~50ohm.
Just to highlight that, a non inductive resistive load of 50ohm (i.e dummy load) with give a near perfect SWR reading yet is a very poor at resonating RF.
My suggestion for a greenlaning/convoy antenna is nothing more than a RF leaky (unshielded) dummy load capable of safely dissipating the heat from ~5watts of power. This can be put on the end of a length of coax and hung/hooked/stuck on suitable location inside the vehicle. The range will vary but should be satisfactory for a few hundred feet line of sight. No worrying about routing cable to outside of vehicle, no worries about tuning, no worries about trees, no worries about mounting and earthing brackets and mounts.
aye, but a crap SWR will total your rig pretty quickly, so you want it idealy under 2:1, nearer 1:1 the better of course.
MW6TLF