Hum from TV Tuner

[keithsebastian]

I get a humming sound from my pc speakers whenever i connect the tv cable to the tv tuner card. It happens even when the audio o/p of the card is not connected to the soundcard i\p.

Specs: Frontech TV tuner+ capture card.
Intel d845wn motherboard with onboard sound.

[keithsebastian]

I guess this may be a ground loop problem. Can anybody pls. tell me how to build a cable(antenna) isolator.

Also the drivers for the tuner/capture card say "Philips" in the manucaturer section. So i guess the chip is a philips product.

[hwoodwar]

You could try "Ferrite Beads" on the cable, sometimes that helps. Another thing would be rerouting the cable away from all possible interference sources. I actually have over 50 percent of the length of my cable attached to the ceiling.

I encountered one unusual source of interference a few weeks ago. I have a UV filter/Glare screen on my monitor, the kind that has a grounding strap. I had the grounding strap connected to the PC case. On certain channels I was getting an interference pattern. It was actually coming through that grounding strap. When I disconnected the grounding strap the interference disappeared.

[The village idiot]

OK, here is a cable tv ground isolator:

Go to radioshack or walmart or where ever and get two 75 ohm to 300 ohm adaptors. Also get a short piece of coax cable with connectors. Then hook the two adaptors together at the 300 ohm ends. It looks like this:


75 ----<==300=300==>----75

Make sure that the 300 ohm ends do not short against each other. Use some electrical tape to insolate them. This works very well, but will reduce the signal strength of the upper channels!