Ok, picture this. A three stiry deluxe apartment building. 1st floor consist of a bar, cyber cafe, movie theater, library, fitness center, hobby room and so on. We installed a nice MA rack in the theater. In the bar we have another MA rack that has all of the house equipment in it. In this rack we have a key digital 3X8 component video distribution. we are sending 1 HD cable box thru and 1 DVD player. We are getting ground hum bars on everything. When we disconnect the coax from the cable box, the bars go away. Even the same problem in the stand alone theater. Switch over to DVD, hum bars, back to cable, hum bars. Disconnect the coax from the cable box. No hum bars. Okay, my first idea was to temporarrily drop the ground wire from the incomming service. There isnt one. The service comes in from the street on a coax, (twice the size of RG/11) then into one of their passive things that has no power and is not grounded, but gets hot, then into their secure box with two 8 way splitters in them. there are two of these boxes on each floor (including the parking garage) so 8 of these boxes, and none of these boxes are grounded either. Our incredibly talented cable provider serviceman showed up yesterday and accused me of running a screw thru one of my video runs. After I blew off some steam, I offered my input of possibly grounding all of these boxes. Well he opens the box that feeds all of our equipment and grounded it. No help. Im at a loss. Time Warner is no help. Do you think grounding each distrobution box will make the problem go away??? BTW each rack has its own Surge and filtering via HTS3600's.

There have been plenty of strings about this problem. The easiest solution is putting some type of ground loop isolator BEFORE the cable box. Since the ground problem is only there when the cable is attached to the system, you have isolated your problem down to the cable feed. Try an RF ground breaking transformer from Jensen inc. or Xantech corp. They work 99% of the time. Good luck.

This will take care of it.

[Link: jensentransformers.com]

Dawn

Ground the Cable wire using a RF Grounding Coupler, like you were grounding a satellite. Run the copper wire to the service panel ground. You could also try a ground breaker from xantech or jensen. I have the Xantech ones in stock If you need one. Due to the fact that you are running source equipment to display equipment, they are probably on different circuits. I would suggest trying to use a Jensen transformer on the component video. I have four composite ones in stock, if you would like to try one, but I will need it back by Friday. Let me know.

Also, runnning the cable line into the MP device will only caus ethe problem to continue. By plugging the cable into the MP, you are now connecting the Cable ground (wherever it is), to the ground in the house. This could also cause a hum in the stereo equipment. Definetly try the Xantech ground breaker on the main cable line, and the Jensen transformer on the component Video.

mike

Thanks Mike. I ordered 12 of the Xantech peices today.