ignition noise

I have an '00 Intrepid and an '02 Stratus, and whenever I try to use a
battery operated CB radio (for trips) or a "ham" radio, whether with
internal or external antenna, I get lots of ignition noise when the car is
running. It's not a "whine" but more like a speed-intensive "pop." The
noise is present even when running of the power outlet. Shut off the
engine, and the interference is gone.

Wondering what I could do to eliminate the noise. Would running the units
directly off the battery (or in my case the positive and negative terminals
in the engine compartment) help.

Thanks for any clues.

 

The ignition pulses are being picked up by the wiring under the hood. Need
to get an ignition filter from RadioShack or similar location, ground it
well, and connect your wiring for your CB/HAM radio through it. If you're
really handy, you can build your own filter from instructions found in any
one of several HAM radio books which should save you some money. Good luck
......

 

Hi Just...

Running it off the vehicle battery - no matter where you
connect it - won't make a bit of difference.

What _might_ help is checking that the hood is very, very well
grounded.

Take care.

Ken

 

Kenwood mobile ham gear like the triband 742 D came with a huge toroid hung
noise suppressor on the power input leads that prevented just about any
noise from getting in that way.

Bond your hood to the body with a hunk a flat ground cable.

Try moving the antenna and coax leading to it someplace else ( I assume you
are using a mag mount ?)

Try making sure your antenna has a good ground.

try an external speaker with a built in DSP noise reduction circuit.

 

Thanks for all the replies. I've tried both mag mount and "set-screw"
mountings for the antenna; no difference. But will check the grounding from
hood to body. I'm inclined to think the noise is being picked up by the
antenna, since it still noisy with internal battery power.

 

ground the unit at the best ground on the vehicle and that's the battery
then make sure the noise u are hearing is not from the plug wires and gm cars
are well known for this issue it even affects other cars radio's at stop lites
water test the plug wires

 

I have from time to time run my Icom IC-706MkIIG in our '02 300M. The
rig is mounted in the trunk, with #6 power wiring direct from the
battery (with a fuse in the +ve lead right next to the battery). I use
an appropriate Ham-Stick (or similar) antenna attached to a trunk-lip
mount. I "bridged" the hood and trunk hinges with battery grounding straps.

I've sometimes detected the ignition interference, but the noise blanker
will usually take it out (and the 706 noise blanker is generally thought
to be far from the best around).

I do have a RadioSchlock "Heavy Duty Noise Filter" ready to install, but
so far I haven't gotten around to doing it.

"Perce"
(aka Alan NV8A)