Interfearance (whine) (CB)

[Deleted Member S]

I've got my CB set up at last in the truck :smile: But with the engine running i'm getting a whine through it which matches the revs :evil: :evil:
I know you used to be able to get surpressers for engine interfearance whine, but never realy had much luck with them in the past :roll:
Has anyone got any idears on how to shut it up :roll:

 

[Matt]

Try this bloke. www.4x4cb.com
Not as cheap as your local truck stop once you add postage but worth it for the advice.
On mine both wires go direct to the battery via a"bandit" interference suppresor.

 

[eclipse]

You should be able to pick up an inline supressor from most car stores, you could also try putting a sleave of insulating tape over the power wires, this some times helps.

 

[Deleted Member S]

You should be able to pick up an inline supressor from most car stores

Is that the type you can get for the back of the alternator :? I've got it powered from the cig lighter socket if that helps :roll:

 

[rustic]

Hi, you actually need an inductor or choke in line with the +ve supply line to the CB, this will reduce the whine. Molyslip will not work in this instance.. :lol: :lol:
They are small coils of copper wire wound round a ferite former, and are available from CB shops, Maplins etc. They are slightly larger than a fuse in a domestic plug. Some are rated by the inductance value (mH etc) , some by their amp rating, you will need one of approx 3 amp rating.
Also check that the earth wire to the CB is adequate and as short as possible. 10-4 Rustic

Just thought I'd add this having read your earlir thread with a burner, if you are powering both the burner and CB off same supply you may need a bigger choke, but I am fairly confident that the 3Amp choke will be ok for the CB on it's own.
You could get earth currents circulating in the cables between the CB and the burner especially the coax, so you may need to experiment a little with where to get the 12V feed and where to earth it. Bolting the CB or burner to metal could also cause a few problems. Re Aerial, you will need to replace the aerial, although you could shorten the aerial to a fraction of the wavelength, eg 1/2 wave or 1/4 wave but not worth the effort, and the efficiency will be well down.

 

[Deleted Member S]

I had a look on Maplins site & found these & wondered if this is what you were on about Rustic :?

An axial lead, lacquer-coated frequency choke 4.7mh choke or 10.0uh :? sorry copied it from the site

 

[rustic]

I had a look on Maplins site & found these & wondered if this is what you were on about Rustic :?

An axial lead, lacquer-coated frequency choke 4.7mh choke or 10.0uh :? sorry copied it from the site

Hi Sweety, no these are too low current, I can't seem to find them in the current Maplins catalogue. They had some in my days of CB radio 8O
I guess you could use ferrite rings and loop the wire several times through, but you would have to experiment a lot.
I'll have another look for you.

Maybe a CB shop will have them.

 

[dinky]

Try Knights http://www.kcb.co.uk/shop2/index1.html VERY GOOD SERVICE.Do mail order as well.

 

[rustic]

Try Knights http://www.kcb.co.uk/shop2/index1.html VERY GOOD SERVICE.Do mail order as well.

Well found Dinky, I looked on the site and under Accessories..... Filters..... you will find a "Hot Line Filter" part X15 at £1.95 +PP this should do the trick.
OR you could print off the spec and take to a local CB Shop and tell him that the noise is altermator based, this is a very common problem with CB's.

As per site notes, this filter will not get rid of interference picked up by the aerial.

 

[Deleted Member S]

Thanks for all the help guys-welldone- -welldone- I will give it a try :roll:
As for the local CB shops all the ones I knew of have went belly up :roll:

 

[rustic]

Thanks for all the help guys-welldone- -welldone- I will give it a try :roll:
As for the local CB shops all the ones I knew of have went belly up :roll:

Truck stops may be a good source, ask a local truckie.... one with a CB aerial..
have a great weekend.. :wink: