2003 Pajaro - HF noise

I forgot my email address:
jaylyle at mac dot com

I was asked to provide more information:

1) The noise is received noise.
2) Radio is Yaesu FT-857D Ham Radio
3) Radio is connected directly to battery.
4) Antenna is on a ball mount in read of vehicle.
5) Noise stops when engine is stopped.
6) Noise does not start when ignition is placed to on (without starting). This probably precludes fuel pump noise.
7) Engine is 3.0 Liter gasoline engine.

Jay Lyle
Shakopee, MN USA

I have the model incorrect - in the US, the Montero Sport is known as the Challenger in Oz.

Hi Jay
Un plug the alternator and run engine this will eliminate or identify another component

Kiwi Ray:
That is a good idea (remove alternator wire). From what I understand, sometimes there are multiple sources of interferences.

G'day Jay - I have a completely different vehicle yet my HF interfenece is chronic and caused by the high tension circuitry associated with the electronic injector system (diesel) - this is indicated by the noise disappearing when I take my foot off the accelerator, while mobile (fuel cut-off). Many vehicles here in Oz have the same problem and most are impossible to control - many of us have to pull over and switch off to use the HF !

This is an often referred to topic and refers to many of the more modern vehicles both petrol and diesel. The interference can be minimized but probably not eliminated by the usual range of measures.
Bonding of body parts and body to chassis including the exhaust pipe.
Rear mounting of the aerial
Clip on and wind through torroids on troublesome leads
Shielding of automotive components
Chokes and bypass caps
Placement of leads in relation to each other
Each measure may only lower the noise a bit but it all counts.
An old portable shortwave receiver with a fettite stick aerial makes a rough indicator of where some of the interference may be located.
Good luck

It will probably be the actual injection system itself, I used to install H F's for a crust and virtually gave up stopping the V6 Pajero's from interfering. As has been said lots of modern vehicles both diesel and petrol will cause uncontrollable interference. TD5 landies are also a problem.
I used to have fun with a mate in a pajero in traffic with my diesel troopy. The old troopy could beat him off at the lights regularly, especially when I picked a frequency around 11 megs and hit the tune button on the HF, the old V6 Paj would get the staggers big time as the RF mucked up the injection system.
A mate with a codan in an L series fuel injected subie had similar probs, sometimes it would cut the engine out. we'd be zooming down the road and then selcall him, his codan would tune before replying and the engine would cut out.

Also check whether you have a electric fan on the radiator. They will cut in and out according to temp and can produce a lot of noise