Motor noise on boat sterio

[dotsadie]

I have put in a new sterio radio on my boat. When i have FM on there is no motor noise, but when i put on AM then there is motor noise.
Have been reading on the internet about this problem and most people say it is a bad ground.So can i run a ground wire from the battery neg; right to the Radio?
If this works will my antenna be grounded as well when it is plug into the radio or will i need to ground the ananten as well?

 

[metriccrescentwrench]

Re: Motor noise on boat sterio

For the most part it's going to be a fact of life that you'll get engine noise when trying to listen to AM stations. You might try a filter on the power going to the radio, there are a few commercially available that don't cost much, but I don't really think they'll be much help. You might be able to help the situation a little bit by running both the positive and negative from the battery directly to the radio also (BE SURE TO PROPERLY PROTECT THAT WIRE WITH AN INLINE FUSE AT THE BATTERY !!!) Boat engines don't have all the RF suppression built into them that car engines do, so you're pretty much fighting a losing battle.

 

[gm280]

Re: Motor noise on boat sterio

I have put in a new sterio radio on my boat. When i have FM on there is no motor noise, but when i put on AM then there is motor noise.
Have been reading on the internet about this problem and most people say it is a bad ground.So can i run a ground wire from the battery neg; right to the Radio?
If this works will my antenna be grounded as well when it is plug into the radio or will i need to ground the ananten as well?

I concur with the above post as well. OB engines don't use resistive plug wires or plugs for that matter and have zero RFI shielding to dissuade any RFI transmissions. So if a good coil/capacitor type tuned filter circuit in the supply lines doesn't work, it means your noise problem isn?t coming from the power supply lines and you are stuck with the problem. You could try to install some foil lining in the cowling for some help. That would help block any RFI transmissions. But if you do, make sure that foil lining is also shorted to the ground of the engine as well. Other than that, you will have to live with it. That IS the reason they went to FM for most of today?s radio stations?less RFI interferences? One thing that is great about AM radios though, is the fact that you can tune your radio to some unused frequency in the lower scale and will know if or when a storm approaches with the lightening interferences you will hear? :watermelon:

 

[sktn77a]

Re: Motor noise on boat sterio

Did the old radio do the same? What brand was the old radio and what brand is the new one? Please don't say JBL, Dual, Boss or Pyle - they are the cheapest Asian cr_p on the market - the manufacturers sold the rights to their names to make a quick buck!

 

[04fxdwgi]

Re: Motor noise on boat sterio

A buzzing sound is usually ignition. Cure is usually resistor wires and plugs.
A high pitched whirring sound is usually the alternator. Cure is normally a filter on the alternator.

 

[H20Rat]

Re: Motor noise on boat sterio

Please don't say JBL, Dual, Boss or Pyle - they are the cheapest Asian cr_p on the market

Name a head unit NOT made in the asian market... (McIntosh doesn't count, have yet to see one in a boat! McIntosh is technically a Japanese brand anyway, owned by Clarion)

Anyway, JBL is decent. Ford used JBL exclusively in the premium systems, now toyota uses JBL in almost every vehicle that rolls off the line. Dual, Boss, Pyle on the other hand, stay away from their head units, but their speakers and amps actually aren't half bad for the price, especially in an open air marine environment where components might not last that long anyway.

In my experience (designed and built quite a few competition winning car audio systems), the problem in a marine environment is almost always non-RFI protected ignition components. Next up is poor wiring. (easy to do in a boat, most common mistakes are too large of gauge and not understanding the importance of a good ground path.) The LAST thing that should ever be done is add filters to the radio. (not saying that isn't ever needed, but only after you exhaust all other avenues.)

 

[sktn77a]

Re: Motor noise on boat sterio

Name a head unit NOT made in the asian market... (McIntosh doesn't count, have yet to see one in a boat! McIntosh is technically a Japanese brand anyway, owned by Clarion).

While I don't fundamentally disagree with anything you say, a single OEM can have several lines of quality. For example FoxConn make the iPhone for Apple; they also make the cheapest, most unreliable generic computer components (video cards, etc) for the no-name PC market.

Frankly, I wouldn't buy any of those brands as they no longer have a reputation to live up to. Unlike SONY, JVC, Kenwood, etc who, while also manufacturing in the cheapest labor markets in Asia, still have a quality name to stand behind.

 

[pckeen]

Re: Motor noise on boat sterio

My Two cents - unfortunately, this is a problem that you may just have to live with - I have a Satellite Radio in the truck, with exactly the same set of issues.