Jackaroo radio interference

Usually an earthing problem either with radio or perhaps the alternator is playing up.

Mal, Two possibilities come to mind:

1. The problem may be the antenna. If the connection to the antenna is dodgy then the incoming radio signal is weak causing the radio to increase amplification to achieve an acceptable audio level. The increased amplification will also amplify the normal background noise. Also be sure that you are tuned accurately to a strong radio station. Try retuning the radio.

2. To check if it is noise generated by the ignition (rather than the alternator) with the radio on and the noise present, rev the engine up to a couple of thousand revs then switch the ignition off (but only to the accessory position so the radio stays on). If the noise ceases instantly when the ignition goes off but the engine is still free-rotating then the problem is probably with the ignition. If the noise continues and fades as the engine speed falls then the problem may be with the alternator.

If it is an ignition problem, check all High Tension leads and connections. A small spark-gap can create a lot of RF noise.

Hi Old Mal,

As a general rule engine noise does not affect FM. It is VHF. Having said that, with out hearing the noise it is hard to define the problem. A good place to start is to make sure your aerial is properly earthed and to cable to it has not been "broken".

Alternators make a squealing noise that increases with revs, it has a different sound to ignition. Holden brought out a filter to fit to Jackaroos because of noise in radio problems, but as I recall that may have been only for diesels.

I would try the radio installer and get him/her to take a listen and go from there.

Good Luck