Sirius Radio Humming

ecoast wrote:
...run the lighter ground to the radio ground = free, and no more ground loop or purchases.

:R

Yeah, right, obviously YOU have never poked your head behind the dash.

Modern day autos BURY the ground wires in the harness, finding the ground wires for radio AND 12V power point and joining them in a common location WILL be an operation of futility.

On top of that, is the fact that the internal grounding point inside the radio on the AUX input may also not be at the SAME ground potential.

The only two ways to fix the problem is to use the ground loop isolator like I linked or run the Sirus radio tuner from a separate power source like a small battery.

...run the lighter ground to the radio ground = free, and no more ground loop or purchases.

Actually, Radio Shack "might" still sell an inline ground loop isolator. Never actually bought one, but borrowed one(:R) from a multiplex theater sound rack for a film festival in DC. Needed to temporarily install a rental Bluray deck on one screen and was getting a hum with RCA audio, no surprise here, when patched into the cinema processor. Apparently, the theater was using them for hum issues with their CD players.

the quickest easiest way to eliminate a ground loop problem is to get a DI box with a ground lift switch and set it to "lift"

Run some wire to the battery and hook it into that. Lighters are notorious for bad grounding also. One could also use a condensor in the line. the quickest easiest way to eliminate a ground loop problem is to get a DI box with a ground lift switch and set it to "lift"

Make sure the FM transmitter is turned off if it is hard wired to the radio.

tatest wrote:
The 12V outlet on the dash is probably not clean power, but there could be other sources of interference, considering all of the other electronic equipment in the chassis.

Does the frequency of the hum change with engine RPM? That signal could be coming from the ignition system or the alternator. There are installation methods to filter this particular interference to ground,or to block both signal sources, usually applied to the wiring for the OEM radio.

It is also possible that something in a nearby part of the spectrum, or a harmonic thereof, is getting into the satellite signal, but that should interfere with reception more than it injects noise. That's way out of my experience, I was working on what were the problems 50 years ago, we weren't trying to pick up signals from satellites.

The problem can be also be in the speakers, if it hums and buzzes regardless of signal source, and that can be as simple as mechanical connection problems.

WRONG, WRONG, WRONG.

It has NOTHING to do with the 12V outlet and "dirty power" nor is it bad speakers or any other items mentioned in the above qoted post.

What the problem REALLY is from is the DIFFERENCE of the GROUNDING between the RADIO and the Sirus radio receiver.

In the audio world it is known as a GROUND LOOP.

The car radio ground connection is located at a different point from the 12V accessory outlet. This causes a slight difference of voltage between the two grounds which causes crazy noises, hum, buzz picked up by the input wire of the car radio.

The easiest way to fix this issue is to purchase a GROUND LOOP ELIMINATOR or ISOLATOR which is nothing more than two one to one isolation transformers. This effectively BREAKS the ground loop.

GROUND LOOP ISOLATOR

The 12V outlet on the dash is probably not clean power, but there could be other sources of interference, considering all of the other electronic equipment in the chassis.

Does the frequency of the hum change with engine RPM? That signal could be coming from the ignition system or the alternator. There are installation methods to filter this particular interference to ground,or to block both signal sources, usually applied to the wiring for the OEM radio.

It is also possible that something in a nearby part of the spectrum, or a harmonic thereof, is getting into the satellite signal, but that should interfere with reception more than it injects noise. That's way out of my experience, I was working on what were the problems 50 years ago, we weren't trying to pick up signals from satellites.

The problem can be also be in the speakers, if it hums and buzzes regardless of signal source, and that can be as simple as mechanical connection problems.

Maybe it doesn't know the Words:B

How Serious is the Radio humming? Sorry, couldn't help it. :BUsually caused by a grounding issue.

Will move your topic to the Technology Corner.