225 Engine Noise on VHF radio

[vrundquist]

Now I am really frustrated! I have installed a new VHF radio and antenna. I get alternator / ignition whine on it when listening to radio traffic. I have replaced the wiring coming from the battery compartment, the antenna is in the same location as the old one. I have replaced the power pack and stator on the engine (for a different problem).

I have made sure the VHF radio antenna wire is away from current carrying wires. I have new batteries.

When I turn the squelch all the way up to listen to static I can hear the noise. When I disconnect the antenna the noise goes away, but static remains.

I am convinced that the noise is from the engine ignition. Any suggestions as what to look at first.

Thanks,

Victor

 

[bktheking]

Re: 225 Engine Noise on VHF radio

Go to a car audio shop and tell them your issue, they will suggest a noise filter suited to your application.

 

[wilde1j]

Re: 225 Engine Noise on VHF radio

If you're not using resistor spark plugs, try that first. They're the Champs with the "Q" designation. If that doesn't work, do the noise filter thing.

i.e.
200, 225, 225HO 1994 - 2001 QL78YC (see note 3) .030"

 

[vrundquist]

Re: 225 Engine Noise on VHF radio

I think I have the Champ QL77JC4 plugs recommended by CDI Electronics in thier leaflet provided with a new power pack. I will check and make sure.

I have already installed a noise filter on the power line going to the radio.

 

[2rz-fte]

Re: 225 Engine Noise on VHF radio

If you're not using resistor spark plugs, try that first. They're the Champs with the "Q" designation. If that doesn't work, do the noise filter thing.

i.e.
200, 225, 225HO 1994 - 2001 QL78YC (see note 3) .030"

i think he means supressor, NOT resistor.

also id check all wires that are ran with other wires. the radio stuff should be ran separate from everything. kinda like a car radio. can you possibly look into shielded ant cable? i think they are all shielded, just a suggestion.

 

[wilde1j]

Re: 225 Engine Noise on VHF radio

i think he means supressor, NOT resistor.

also id check all wires that are ran with other wires. the radio stuff should be ran separate from everything. kinda like a car radio. can you possibly look into shielded ant cable? i think they are all shielded, just a suggestion.

Resistor plugs are noise suppressors.

Virtually all VHF and CB antenna cables are shielded. It's very important to keep the antenna cable well separated from all other power wiring, since any electrical noise picked up by the antenna or antenna cable will otherwise be impossible to kill. You may find a better antenna/cable may help. Also, make sure all antenna connections are very clean and tight.

Is the radio noise a new feature, or did it just begin?
If it just began, what has changed electrically?
Did you have an old VHF and antenna? (Have you tried the old antenna ... don't install, just connect it).
Is all of the wiring (power and antenna) associated with the VHF well forward in the boat?
If you can determine whether the noise is getting to the VHF via the antenna, there are VHF specific noise filter available. [From your description, it appears the noise is coming via the antenna].

 

[2rz-fte]

Re: 225 Engine Noise on VHF radio

i thought suppressor plugs were inductor type while resistor plugs are resistor type?

either way, what this discussion is going towards is, we hope youre running the correct spark plug for your application. it can play a big role.

check your grounds too. those things always give me problems.

 

[Vic.S]

Re: 225 Engine Noise on VHF radio

Resistor plugs are noise suppressors

. But low resistance, inductively suppressed, plugs must the used with OMC CDI ignition systems.

Ordinary resistance suppressed plugs are not suitable.

The Q series are the correct ones ( R series are not)

 

[vrundquist]

Re: 225 Engine Noise on VHF radio

I [ut the Q series plugs in and no more noise!