In an electrical system, a ground loop or earth loop occurs when two points of a circuit are intended to have the same ground reference potential but instead have a different potential between them. Ground loops are a major cause of noise , hum, and interference in audio, video, and computer systems. Wiring practices that protect against ground loops include ensuring that all vulnerable signal circuits are referenced to one point as ground. The use of differential connections can provide rejections of ground-induced interference. Removal of safety ground connections to equipment in an effort to eliminate ground loops also eliminates the protection the safety ground connection is intended to provide. A ground loop is caused by the interconnection of electrical equipment that results in there being multiple paths to ground, so a closed conductive loop is formed.
Ground loop Isolator on 12v line?
Groundloop information pages
Antenna cable isolator is basically quite simple circuit but it must be built correctly. Improperly built antenna isolator can can cause RFI problems and even screw up the building antenna network operation. Antenna isolators work at very high frequencies up to MHz where even a very small construction details and component specifications can have a highe difference on circuit operation. If you are not experienced and knowleadge at building high radio freqeuency circuits, I recommend that you buy a ready made isolator instrad of try to build it yourself. This solved the hum, no need for a messing with the audio signal, and the tv image quality did not suffer most tv's get an overdose of signal from the cable tv anyway. You can simply make such a transformer: Take two strands of insulated wire, length: cm. Twist the two wires, about twists per cm is enough.
How to Install a Ground Loop Isolator
A ground loop, which is created when two or more pieces of connected, grounded equipment are drawing power from the same source, can cause an annoying humming sound that comes through your guitar amplifier. The safest and easiest way to eliminate the noise in either a recording or performing environment is to connect the amp to a direct box en route to the mixing board. Locate the output on the amplifier. Plug the XLR cable into the direct box's output and connect the other end of the cable to the live or recording mixer.