power supplies with minimal radio interferance?

**dyne** · 02-27-2009, 05:43 PM

My m2atx no longer survives cranking, so I figured I'd get a new power supply and hopefully fix my radio reception problem (I can't get any radio stations with my carputer on). I already have the carputer fully enclosed in an aluminum Mo-Co-So case, but that doesn't block the radio interference.

Are there any power supplies out there that don't really interfere with the radio?

**blade828** · 03-03-2009, 03:09 AM

My m2 doesn't give any interference at all. I kept all power wires separate from signal wires.

**will1384** · 03-03-2009, 04:01 AM

There is always a little interference form a carpc, but it should be
unnoticeable unless you max out the volume playing a blank sound file
and even then it should be really low

I think you have a wiring problem, check all your grounds
and yea keep power wires on one side of the car and audio
cables on the other, dont run them together

**dyne** · 03-03-2009, 09:07 AM

Originally Posted by will1384

There is always a little interference form a carpc, but it should be
unnoticeable unless you max out the volume playing a blank sound file
and even then it should be really low

I think you have a wiring problem, check all your grounds
and yea keep power wires on one side of the car and audio
cables on the other, dont run them together

The problem isn't the audio cables; I'm using the Directed HD radio module and it's unable to lock on any stations when the carputer is on, but a dozen or so when the carputer is off. I believe it's either radio interference or maybe some sort of electrical interference over the +12v line (I don't know if that's possible, I'm just speculating). The HD radio module is mounted in my trunk (the carputer is under my passenger seat)...there is a stereo cable running to the carputer and a 12v line coming from the carputer to power the HD radio module.

I'm also using an aftermarket antenna that's inside of my car's cabin on the rear deck lid (the factory antenna was pretty ugly). I know I can't expect as good reception with the aftermarket antenna, but the fact that I can lock onto stations with the carputer off tells me there's some sort of interference going on. I supposed I can try grounding the antenna at a different point in case the point it's currently grounded to isn't great.

**WuNgUn** · 03-03-2009, 10:40 AM

What kinda gauge power wiring are you running to the M2?
Why not build a Faraday cage around the M2, or at least check our cable runs?

**durwood** · 03-03-2009, 11:22 AM

Have you tested your carputer with a regular desktop power supply plugged into 110(AC-DC) to verify the M2-ATX was causing RF reception interference? Friend of mine has the same issue but I haven't had time to help him troubleshoot this issue yet to determine if it's the PS or the PC.

**WuNgUn** · 03-03-2009, 12:31 PM

That's a good point Durwood...in a car, RF noise can be coming from any number of areas...

**nrgizerbunny** · 03-03-2009, 01:14 PM

i get EXACTLY the same problem with my M2ATX, what I did was fed the HD radio a separate supply from another car battery, turned the carputer on and the radio reception went cack.

I then repeated the experiment with a DC power supply feeding the M2ATX, same result

I finaly repeated the experiment with a standard ATX supply feeding the Carputer - i removed the M2-ATX. THe prbolems went away.

I have since ordered an Opus PSU as i've been told these have the lowest RF interference - they were originally designed for emergency vehicles.

**WuNgUn** · 03-03-2009, 01:33 PM

Opus FTW!!!!

Yet ANOTHER testimonial as to the ****tiness of the M2/M4...

**will1384** · 03-03-2009, 02:13 PM

Originally Posted by dyne

The problem isn't the audio cables; I'm using the Directed HD radio module and it's unable to lock on any stations when the carputer is on, but a dozen or so when the carputer is off. I believe it's either radio interference or maybe some sort of electrical interference over the +12v line (I don't know if that's possible, I'm just speculating). The HD radio module is mounted in my trunk (the carputer is under my passenger seat)...there is a stereo cable running to the carputer and a 12v line coming from the carputer to power the HD radio module.

I'm also using an aftermarket antenna that's inside of my car's cabin on the rear deck lid (the factory antenna was pretty ugly). I know I can't expect as good reception with the aftermarket antenna, but the fact that I can lock onto stations with the carputer off tells me there's some sort of interference going on. I supposed I can try grounding the antenna at a different point in case the point it's currently grounded to isn't great.

Sounds a little odd, I could see the antenna being inside the cab
could be a problem, should be outside, but I am one to talk I have
my Wi-fi antenna in the same place.

Every time I have had a problem like that, its been a wiring problem,
ether a lose wire, connector, or bad ground, I sometimes end up
having to pull/tug on the wires to check for that, just don't pull to
hard, but you would try something like that with the system on and its
messing up, to see if by pulling or moving the wires the problem
changes, I also have had grounds in a car be bad, and have to
remove the paint from the metal to get a good ground, might also
want to check under the hood, might have corrosion on the
battery terminals or wires, -use some Vaseline to help prevent that -
or the wires or grounds under the hood may be rusted/ corroded.

I suspect its a grounding problem

Check this link out might help

Ground loop problems and how to get rid of them