HF noise from Turbo Disel

Hi Barry, try this Site Link
Murrays a mate of mine.
Also the Yahoo Codan group can be helpful with c/r diesel interference.

We occasionally got this problem back in the days when I was fitting two-way radios. All the usual engine suppression (petrol motors) failed to eliminate the problem. It turned out to be statics in the exhaust system. This happens in piston engines in aircraft as well.

Get some coper braid - the outer conductor from co-axial cable will do. Attach one end to the end of the exhaust pipe with a hose clamp and and the other end to a good earth on the body or chassis.

PeterD

I have read about such problems with electronic diesels on amateur radio websites and the cures they have come up with.It usually involves ferrite chokes
amongst other things.

I assume you've got the new V8. It was a well recognised problem on the 1HD-FTE in both the 100series and 78/9 series. Mine was unusable when mobile, having been previously fine on the TD Prado.

I went around with a multimeter and ended up putting earth leads on both fuel tank covers and the rear end of the exhaust. I sought advice from Electric Bug in Adelaide, and he had nothing further to advise, apart from adding a noise-reducing speaker. So I bit the bullet, spent over $300 on one and I've been happy with the way it works. It has 3 levels of noise reduction, and the first level is all I use - if I move to 2nd land 3rd level it cuts out the voices. I use it on noise reduction all the time - even when stationary.

If you follow the link you'll find that its not just a matter of earthing. The relatively high switching voltage around the ecu and injectors point to shielding and suppression in addition to the normal earthing needs.

Barry
my fridge also creates noises that sound like noises from a distant Galaxy too , I overcome that by fitting a switch on the roof console so when I want to use the radio for the Sked I just turn it off, Forgot to turn it back on once and the bloody T Bones thawed out a bit ,\As for the engine noise , yes I get it too , 75 series

Having fitted HF's for a crust a while back (stopped about 6 years ago) the biggest source of noise on diesel cruisers is the sender for the oil gauge. LHS of the engine you will see what looks like a little tin can with a wire connected to the centre terminal, some have an earth terminal as well. Connect a 1 uF capacitor between the two terminals or between the centre terminal and the case.
I used to solder them to the terminals and insulate/stick the cap to the side with silicone to secure it.
Everything else electrical will cause noise as well, we used to turn everything off, pull up and stop the engine if a selcall came in.
GPS CPU's also cause interference as do inverters, laptops and reversing screens.
Make sure that the bonnet (across the hinges), doors (hinges also)and the exhaust system are also earthed with braid, the latter at the front, centre and rear to prevent static buildup.

Attenuating noise will attenuate the signal which you dont want. There is a trick used by some involving an am radio tuned off channel and short antenna wire and go around the engine bay looking for the noise source. If you cant find a way to stop the noise look to fitting the antenna to the rear of the vehicle. I had to do this on an old Hilux I owned.

Owen

Thanks for all your replys they are appreciated
I will start with the earthing and see where that takes me
Cheers
Barry