Terrible radio interference, out of ideas.

Pontoonfoon

Seaman
Joined
Apr 28, 2010
Messages
69
I have a radio and 4 speakers, the radio runs DIRECTLY off of a deep cycle battery, and that is the ONLY thing that is on the deep cycle. everything else is on the cranking battery.

with everything else off the radio gets excellent reception.

with the motor running, the radio gets excellent reception.

if I turn on my depth finder.. I get alot of static on the radio..

if I plug my aerator into 12V cigarette and turn it on, I get tons of static on the radio, even more so than from the fish finder.

Iv never tried turning on BOTH at the same time, perhaps it summons a lake troll or something..

at any rate, ive changed out the radio, and the antenna to no avail..

what could be causing this
 

turbinedoctor

Petty Officer 1st Class
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Sep 7, 2009
Messages
225
Re: Terrible radio interference, out of ideas.

Do you have the negatives of the two batteries tied together or the power wire of the depth finder or the aerator next to the radio wires and antenna?
 

Pontoonfoon

Seaman
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Apr 28, 2010
Messages
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Re: Terrible radio interference, out of ideas.

Do you have the negatives of the two batteries tied together or the power wire of the depth finder or the aerator next to the radio wires and antenna?


no I do not have the 2 negatives tied together, should I?

the radio, depth finder and aerator wires all right in the same area under the console (within a foot of each other)
 

turbinedoctor

Petty Officer 1st Class
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Messages
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Re: Terrible radio interference, out of ideas.

The negatives do not need to be tied together.

You may want to try to seperate the radio wires from the others and see if that helps. Could be induced interference.
 

bruceb58

Supreme Mariner
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Mar 5, 2006
Messages
30,581
Re: Terrible radio interference, out of ideas.

Try running a seperate ground back to the deep cycle battery. Since the power of the radio goes straight to that one battery and it is the only load, that won't need a filter on it.

How is the deep cycle battery grounded? Just a strap to the main battery?
 

Pontoonfoon

Seaman
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Apr 28, 2010
Messages
69
Re: Terrible radio interference, out of ideas.

Try running a seperate ground back to the deep cycle battery. Since the power of the radio goes straight to that one battery and it is the only load, that won't need a filter on it.

How is the deep cycle battery grounded? Just a strap to the main battery?


the RADIO is running DIRECTLY to the deep cycle, both power and ground. nothing else is powered or grounded to that battery.

the deep cycle is not grounded in any way, its just sitting there.
 

azdcm

Cadet
Joined
Dec 12, 2008
Messages
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Re: Terrible radio interference, out of ideas.

Is this a am/fm radio and if it is what type of ant do you have on it?
 

Pontoonfoon

Seaman
Joined
Apr 28, 2010
Messages
69
Re: Terrible radio interference, out of ideas.

Is this a am/fm radio and if it is what type of ant do you have on it?

Its a Sony AM/FM/HD/XM

before the sony it had some POS "Dual" radio in it.


Ive tried a few different antennas, the one I stayed with is a 12V amplified antenna.
 

TerryMSU

Senior Chief Petty Officer
Joined
Jul 31, 2007
Messages
743
Re: Terrible radio interference, out of ideas.

Both noise items are connected directly to the same battery as your radio uses, right. The most likely cause is conducted, not radiated interference. Can you temporarily try either of those devices on the other battery? (For example, attach a temporary cigarette lighter plug to the starting battery and then plug the aerator into that plug.) If the problem dissappears when the radio is on a different battery from the offending source, that almost certainly confirms that this is a conducted interference issue. If so, try putting a line interference filter (electrical choke) on the power line for either the radio or the offending source.

If there are any questions, please respond here. You can drop me a PM, as a heads up, but this is where I will answer. By the way, this is the kind of thing I deal with for a living (in the automotive realm).

TerryMSU
 

turbinedoctor

Petty Officer 1st Class
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Sep 7, 2009
Messages
225
Re: Terrible radio interference, out of ideas.

I have a radio and 4 speakers, the radio runs DIRECTLY off of a deep cycle battery, and that is the ONLY thing that is on the deep cycle. everything else is on the cranking battery.

with everything else off the radio gets excellent reception.

with the motor running, the radio gets excellent reception.

if I turn on my depth finder.. I get alot of static on the radio..

if I plug my aerator into 12V cigarette and turn it on, I get tons of static on the radio, even more so than from the fish finder.

Iv never tried turning on BOTH at the same time, perhaps it summons a lake troll or something..

at any rate, ive changed out the radio, and the antenna to no avail..

what could be causing this

The radio being the only thing on this battery tells me it is most likely some type of induced noise. You can try to run a temperary wire to feed the radio from a different route to see if this helps. If it does then you know where the problem is.
 

Pontoonfoon

Seaman
Joined
Apr 28, 2010
Messages
69
Re: Terrible radio interference, out of ideas.

The radio being the only thing on this battery tells me it is most likely some type of induced noise. You can try to run a temperary wire to feed the radio from a different route to see if this helps. If it does then you know where the problem is.

I dont follow your logic..


the radio works perfectly except when the fish finder and or the aerator are on..

those 2 are on the cranking battery, the radio is on its own deep cycle..

from a different route you mean.. what? run it from the same battery but take a different path to it avoiding close proximity to the other wires?

I can do that to a point, but when I get to the radio itself there is no way to avoid everything being pretty close.
 

Pontoonfoon

Seaman
Joined
Apr 28, 2010
Messages
69
Re: Terrible radio interference, out of ideas.

Both noise items are connected directly to the same battery as your radio uses, right. The most likely cause is conducted, not radiated interference. Can you temporarily try either of those devices on the other battery? (For example, attach a temporary cigarette lighter plug to the starting battery and then plug the aerator into that plug.) If the problem dissappears when the radio is on a different battery from the offending source, that almost certainly confirms that this is a conducted interference issue. If so, try putting a line interference filter (electrical choke) on the power line for either the radio or the offending source.

If there are any questions, please respond here. You can drop me a PM, as a heads up, but this is where I will answer. By the way, this is the kind of thing I deal with for a living (in the automotive realm).

TerryMSU


I have a radio and 4 speakers, the radio runs DIRECTLY off of a deep cycle battery, and that is the ONLY thing that is on the deep cycle. everything else is on the cranking battery.

the radio is on its own deep cycle battery with nothing else connected to it.

the radio has its own battery.

the radio has a deep cycle battery that is not connected to any other device.
 

TerryMSU

Senior Chief Petty Officer
Joined
Jul 31, 2007
Messages
743
Re: Terrible radio interference, out of ideas.

Thanks for clarifying the situation. Given that situation, it is not a conducted issue. As far as the aerator, a device called a capacitor across the power terminals may improve its issues. Here is what I see most likely happening...

The wired to and from the offending devices are acting as "transmitting antennas" for the interference. I would try to put a powerline filter as close as possible to the offending devices. Keep the wires as short as poossible between the filter and the trouble makers. The other, more troublesome possibility is that the troublemakers are themselves the "antenna". If that is the issue, the fix is a lot more tricky, and may be beyond my skill to help from a distance (or maybe even close up.) To rule this out, try wrapping the offending device in aluminum foil and then grounding the foil. That will shield the offending device, and if it clears up the noise, you have found the problem.

By the way, is the noise AM, FM, etc? Does it show up in the CD (asuming it has one)?

Good Luck,
TerryMSU
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,581
Re: Terrible radio interference, out of ideas.

the RADIO is running DIRECTLY to the deep cycle, both power and ground. nothing else is powered or grounded to that battery.

the deep cycle is not grounded in any way, its just sitting there.
Are you running the power/ground pair alongside any other wires? One thing you can do is create a twisted pair for your power ground going back to your battery. Chuck two wires into your power drill and run the drill until you get the desired twist.
 

Pontoonfoon

Seaman
Joined
Apr 28, 2010
Messages
69
Re: Terrible radio interference, out of ideas.

Are you running the power/ground pair alongside any other wires? One thing you can do is create a twisted pair for your power ground going back to your battery. Chuck two wires into your power drill and run the drill until you get the desired twist.

the power and ground from the deep cycle are 10 gauge and are twisted together.
 

turbinedoctor

Petty Officer 1st Class
Joined
Sep 7, 2009
Messages
225
Re: Terrible radio interference, out of ideas.

What I was refering to is to run a temperary power and neg wire from the deep cycle to the radio as far away from other wires as possible to try to reduce any outside noise.
 

John_S

Rear Admiral
Joined
Jun 21, 2004
Messages
4,269
Re: Terrible radio interference, out of ideas.

Ive tried a few different antennas, the one I stayed with is a 12V amplified antenna.

Did you have the noise on the other antennas? Is the amplified powered from the same deep-cycle as the radio?
 

RickJ6956

Petty Officer 1st Class
Joined
Jul 18, 2009
Messages
349
Re: Terrible radio interference, out of ideas.

Is the noise there on all of the bands (AM, FM, HD, and XM)?

Is this more than a radio (CD, MP3, USB, etc.)? If so, does the noise show up when the other sources are selected?

Is there an external amplifier? If so, is the noise there when the radio's volume is turned all the way down?
 

Pontoonfoon

Seaman
Joined
Apr 28, 2010
Messages
69
Re: Terrible radio interference, out of ideas.

Is the noise there on all of the bands (AM, FM, HD, and XM)?

Is this more than a radio (CD, MP3, USB, etc.)? If so, does the noise show up when the other sources are selected?

Is there an external amplifier? If so, is the noise there when the radio's volume is turned all the way down?

the noise is on AM and FM stations, everything else is very clear

the powered antenna is grounded to the same ground as the radio and is powered by the radio.

the other antenna had the static issue aswell.

no external amp.
 

fishrdan

Admiral
Joined
Jan 25, 2008
Messages
6,989
Re: Terrible radio interference, out of ideas.

Sounds like your have a "ground loop". As suggested earlier, connect the battery grounds together and see if it resolves the problem.
 
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