Do I need an earth?

[Curly]

I just installed a CB in my 3rd gen Surf, and I welded the ariel mount to the swing away spare wheel carrier frame yes I know my welding is crap! Lol!
I am trying to SWR it in but I'm getting a reading of 2.5-3 ish which is turd.

My question is, do I need to run an earth wire from the spare wheel carrier to the surf body itself or would it already be earthed through the hinges/clasp thing?

Cheers,

CURLY

[Tallyman]

First off it looks like you've painted the bracket. If so, that may be what is causing your bad earth. Try cleaning it back to bare metal where the aerial mount will sit, so you have a good connection, then try to SWR it. If that works, problem solved. If not, then yes, try adding an earth wire from a clean bare part of the bracket to a good earth point on the car.

[Curly]

I did clean the bracket where the dome mount connects, but its still high. I was going to connect the actual wheel carrier to the chassis rather than the bracket itself too, with some 6mm˛ wire. reckon that will do the trick? i read up on 4x4cb.com that it is better to earth away from the ariel connection rather than straight onto the bracket..

Cheers,

CURLY

[mr.rosco]

I did clean the bracket where the dome mount connects, but its still high. I was going to connect the actual wheel carrier to the chassis rather than the bracket itself too, with some 6mm˛ wire. reckon that will do the trick? i read up on 4x4cb.com that it is better to earth away from the ariel connection rather than straight onto the bracket..

Cheers,

CURLY

Off the top of my head I think that the spare wheel bracket moves on roll pins in which case you will not get a good earth parth through them. Adding the supplimentry earth cable will work. You might get a good enough connection just running a bit of cable to bypass the pins. Also 6mm cable is quite large in terms of earthing you might find a much smaller cable will also give you the desired effect, however a big cable wouldn't be a bad thing

[LCR225]

Nice mount. Is that something you made yourself?

[Curly]

Nice mount. Is that something you made yourself?

Hi there, yes I did. It started off as a 100mm piece of 50x10 box section. I then cut the circular ends out with hole saws. Cut the bottom middle bit out with a hacksaw, filed it down, welded it on and sprayed it up! Easy peasy!

Cheers,

CURLY

[Apache]

Regards RF performance, that position is always going to be less than optimum anyway, though it is very convenient and is where I mounted mine on my old truck. If you are going to provide it with an earth bond, use thick earth braid rather than cable, as cable can easily be high resistance at HF, even if it looks like a short at DC.

Might be worth playing about with the length of your antenna to tweak your reverse power. If you use a length of stiff wire and a 'choc-blok' connector you can lengthen it to see what that does. If no luck, start to shorten the antenna bit by bit.

A better plan is the roof, as a rod / whip antenna works better with a large, flat ground plane.

[Curly]

Hi Apache, I tried using a jump lead from the tow ball onto the wheel nuts on the wheel carrier and my SWR went down to 1.5 which is pretty good. I reckon for the amount I use the CB for, I'll stick with where it is and just earth the wheel carrier to the body some how. I was going to use 6mm cable left over from my old car stereo days, but if you reckon using an earth braid would be better, I will pop to Halfrauds and get one of those instead.

Thanks for the advice.

CURLY

[mr.rosco]

if you reckon using an earth braid would be better, I will pop to Halfrauds and get one of those instead.


CURLY

Hey Curly if Halfords don't sell earth braids let me know and I will pick you one up from work.

[Curly]

Hey Curly if Halfords don't sell earth braids let me know and I will pick you one up from work.

Nice one, thanks mr rosco!

I'll go have a looky tomorrow and let you know.

Can you get custom lengths etc?

Cheers,

CURLY

[mr.rosco]

Nice one, thanks mr rosco!

I'll go have a looky tomorrow and let you know.

Can you get custom lengths etc?

Cheers,

CURLY

There are two types we use one is about 330mm with 6mm lugs at each end and the smaller type is about 100mm with 6mm lugs at each end. you can join them together with 6mm bolts but it doesn't look pretty. Also if you want to check continuity between different points on the truck to find the best place to earth I could help you with that, my job is electrical testing and comissoning but by the sounds of it high frequency resistance is different to the type of resistance we deal with in electrics. How are you imagining it at the moment? I am considering doing the same thing with mine. I was thinking mabe tap a 6mm hole in the bracket as close to the hinge as possible and bolt the braid straight in to the hinge, then using a 12mm open grommet to go through the bumper and attach straight on to the chassis but I would have to have a look in day light.

[Curly]

I was thinking of drilling and tapping the cast hinge of the wheel carrier, and fixing it straight to the wheel carrier itself. But whether the cast hinge is a good enough earth, I don't know. How could I check it? Could you show me?

I reckon one of those 100mm long braids would work a treat if you could get me one?? ;0) I'll sort you out a beer for it or something?

Cheers,

CURLY

[mr.rosco]

I was thinking of drilling and tapping the cast hinge of the wheel carrier, and fixing it straight to the wheel carrier itself. But whether the cast hinge is a good enough earth, I don't know. How could I check it? Could you show me?

I reckon one of those 100mm long braids would work a treat if you could get me one?? ;0) I'll sort you out a beer for it or something?

Cheers,

CURLY

Sure thats fine, I'll pick up a couple of short ones and a long one tomorrow. We can use my continuity meter to check the earth point, if you need a large flat ground plate then the chassis and underneath of the truck would be best I think? Maybe Apache could clarify this. What we can do is check continuity between the hinge / bracket and the chassis and start from there.

[Curly]

Sure thats fine, I'll pick up a couple of short ones and a long one tomorrow. We can use my continuity meter to check the earth point, if you need a large flat ground plate then the chassis and underneath of the truck would be best I think? Maybe Apache could clarify this. What we can do is check continuity between the hinge / bracket and the chassis and start from there.

Excellent, cheers Mr Rosco! I'm up in Warwick tomorrow, but should be home by 6. What's the plan?

[mr.rosco]

Excellent, cheers Mr Rosco! I'm up in Warwick tomorrow, but should be home by 6. What's the plan?

I am working till 6 tomorrow so i could meet you about 7 onwards or I can do any time after about 5 on Saturday, Sunday I am busy all day but I could also do any night next week after 7. So whatever suits you. I propose to meet outside the Cricket Pitch which is on the Lane next to Wolvens Lane opposit the Plough pub in Coldharbour. This is roughly in the middle of both of us I think.