Hi everyone!
Below you can see the configuration I have at home. Since I've connected the television to the Sat system of the building, I'm experiencing an annoying 50Hz buzz, probably deriving from a ground loop.
A transformer on the sat side is not a solution because it also requires DC to pass; A filter on the audio side isn't a solution either because it will affect audio quality; removing one of the two ground connection is obviously out of the question...
Do you have any smart solution to solve this problem?
Below you can see the configuration I have at home. Since I've connected the television to the Sat system of the building, I'm experiencing an annoying 50Hz buzz, probably deriving from a ground loop.
A transformer on the sat side is not a solution because it also requires DC to pass; A filter on the audio side isn't a solution either because it will affect audio quality; removing one of the two ground connection is obviously out of the question...
Do you have any smart solution to solve this problem?
Attachments
1. Using Isolation transformer. Plug the isolation transformer to the SAT power side first then the rest of your system to the Isolation transformer. This video will explain further
YouTube
2. Using balanced connection instead of unbalanced
3. Start lifting the ground of each component one by one until the hum goes away. Although this is not recommended due to safety issue.
Hope it helps
-Tom
YouTube
2. Using balanced connection instead of unbalanced
3. Start lifting the ground of each component one by one until the hum goes away. Although this is not recommended due to safety issue.
Hope it helps
-Tom
Disconnect the SAT cable except when you watch TV.
Or, try a Jensen VRD-1FF. Why does your SAT signal path need to pass DC? SAT ground needs "DC," but that should happen at the SAT antenna on the roof, per electrical code. Since you have ground hum, the antenna is grounded and you can safely break the coax SAT ground in your house.
You can try grounding the SAT cable ground (coax connector) to your mains power ground with a wire if you know what you're doing. The faceplate screw of an electrical outlet is an OK ground for a test. But if that doesn't work then disconnect or filter.
Or, try a Jensen VRD-1FF. Why does your SAT signal path need to pass DC? SAT ground needs "DC," but that should happen at the SAT antenna on the roof, per electrical code. Since you have ground hum, the antenna is grounded and you can safely break the coax SAT ground in your house.
You can try grounding the SAT cable ground (coax connector) to your mains power ground with a wire if you know what you're doing. The faceplate screw of an electrical outlet is an OK ground for a test. But if that doesn't work then disconnect or filter.
I experienced a similar issue twice already. There may be a fault on the protective ground connection on some other apartment of the building. A small ground current is flowing from the TV-set EMI filter of that apartment to the shield of the antenna cable, and then is finding its way trough the ground connection of your TV/audio gear. Disconnect the antenna cable and touch the wall antenna socket with a current leak tester (such as the old style neon bulb screwdriver we call "cercafase"). If the fault is confirmed, you need to either remove the source of this fault current, or use a digital optical cable from your TV to the amplifier. TosLink to RCA analog converters are cheap. As alternative, add an insulation transformer to lift your entire TV/audio gears from ground. It is best avoided because it is bulkier and more expensive, and also by doing so, the main RCD of your apartment will not trip if you ever happen to touch both mains conductors after the insulation transformer.
Thank you! This did the trick! This was exactly the kind of smart solution I was looking for.
I used a 100ohm resistor (I also tried 1kohm, but it was too much). It is low enough for the control DC signal to pass, but high enough to reduce the hum to an insignificant level.
Thanks to everyone for the interesting answers.
Am I experiencing deja vu here?!
A 10 ohm resistor inserted into the shield of the aerial cable as I recall.
Someday, someone will report back that it works!
EDIT - They just have!!!!!!
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