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AM Radio interference from shore power

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I have a 2006 250CR. When attached to the shore power, I cannot use AM Radio because of the noise/interference. I assume this is because the radio is installed right next to the power panel. Does anyone know of a technique to shield the radio and/or antenna from this interference?

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I have a 2006 250CR. When attached to the shore power, I cannot use AM Radio because of the noise/interference. I assume this is because the radio is installed right next to the power panel. Does anyone know of a technique to shield the radio and/or antenna from this interference?

 

 

The very nature of AM (Amplitude Modulation) makes it very susceptible to any noisy electrical connection or components.

Is the AM radio clear when the boat is not connected?

If yes, then the problem could be in the boat or power panel.

 

Plug something other than your boat (or someone else's boat) into the power panel.

Does the noise re-appear?

If yes check all connections for corrosion and tightness, REMEMBER ELECTRICITY LOSES WATER. (take precautions)

 

If not the problem is in the boat (which is what my choice would be if forced to guess.)

 

Now is the time for harder detective work. Turn off everything the shore power feeds and start re-connecting them one at a time.

When the noise starts that is the culprit.

Check ALL connections for corrosion and tightness.

 

I am going to guess you find out it is the battery charger.

Unfortunately, short of changing whatever is causing the problem you are probably stuck.

I know of no shielding that will clear up environmental noise.

You will most likely be forced to listen to FM or satellite radio.

 

Hope this helped.

 

Keep me posted on your progress.

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Go to next paragraph...this one is just the thinking.....Didn't we, at one time, in cars put across Pos and Neg at alternator a 4.7 uFarad capacitor to cancel....sink the noise to ground. If your noise is from the batt charger you might try this 1960/70's tried and true technique....whats happening is the ripple voltage on top of the charge from the batt charger is being picked up by the amplification circuits of the radio ant thats what you are hearing. A more technical way would be to build and RC circuit of resistor and Capacitor and put it at the 12vdc input to the radio.....better yet,

 

Get a power side noise "Choke" and install it in the 12vdc input...if you have a memory and constant put one on each side of the Radio power. this ought to solve your problem. You can find these at radio shack last time I checked, about 10 years ago....Most new stereos have them installed on the power side already. Its a square box, inline on the 12VDC side(s).

 

If its a radiated "antenna" noise... what I am suggesting won't help....what I suggested will clean the line noise a charger or something may be putting on the 12vdc side. Good luck with it.

 

Like the previous post said....ENSURE every ground is clean and tight. Thats where Noise comes from 99% of time, be it Boat, car, airplane or house,....

 

You will not ever get AM perfect because there is always some "noisy" widget putting out noise close to AM assigned frequencies. Keep us posted. We'd all like to learn...

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I have a 2006 250CR. When attached to the shore power, I cannot use AM Radio because of the noise/interference. I assume this is because the radio is installed right next to the power panel. Does anyone know of a technique to shield the radio and/or antenna from this interference?

 

My simple solution was to turn off shore power when I wanted to listen to the AM radio. I used this solution all summer. Then I found another solution. The factory installed radio is a Kenwood KTS-300MR with a SIR-KEN1 Sirius Radio tuner. This radio is also HD-Ready, so I purchased a KTC-HR200 HD radio tuner that daisy-chains off the SIR-KEN1. That got rid of the AM noise on the stations in Chicago that broadcast HD radio and improved the quality of the sound on FM HD stations.

 

But I learned much more!

In the process of installing the HD Radio, I discovered that the antenna for my radio is a simple wire about 4' long. It is shielded for about the first two feet and then the last 2' is split into two thin wires that can be spread like a simple indoor "T" FM antenna. All of this was just stuffed behind the radio with all the wires for the cabin's power and switches. All I had to do was move that antenna away from that area and most of the noise went away on analog AM radio. It was easy to tuck it behind the galley cabinets.

 

Hope this information helps others.

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