Sirius Radio Humming
Hello, I installed Sirius Starmate 8 radio in my Winnebago Sightseer. I use the 12v outlet on the dash for power and connect to the radio speakers using the supplied accessory wire. I am getting se...
Forum Discussion
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
