Cable grounding and my Ep2500

**Blktre** · **02-24-09, 04:19 PM**

Hi guys, I need some advice.

I get a huge ground loop hum using my ep2500 through my sub rendering the system useless. When I disconnect the coax from the back of the cable box, ground loop hum goes away and I can use my system. I can add a cheater plug to the ep2500, and it works perfectly while the coax IS Connected to the cable box. Remove the cheater plug, no go. Connect the coax, no go. The ep2500 is on a different 20amp outlet as the processor, and cable box, but on the same circuit.

I went outside to check grounding. The cable company has their phone, cable, and internet (I get all 3 services from my cable company) grounded with straps to the conduit of the meter mast. Of course the meter/house is grounded with a long copper solid pipe into the ground.

Is having the phone, cable, and internet grounded to the mast a proper ground? Can I possibly be getting ground loop hum caused by this bad or incorrect grounding method? My cable company wont even come check out their grounding, as they don't ground anything, my electrician grounded everything. I did not hire a electrician to ground their equipment on the outside of my house. I watched them add these ground straps myself.

Any input would be very helpful as I will have to pay an electrician to come check their work and all grounds.
Thanks ahead of time...

Andy

**lcaillo** · **02-24-09, 05:57 PM**

It should be connected directly to the ground rod or the ground wire going to the rod. It may be getting a good connection, but I would measure it. Make sure that the circuits are on the same side, preferably adjacent in the meter panel.

**Blktre** · **02-24-09, 06:59 PM**

Thanks lcaillo, I thought it should be grounded to the ground rod as well.

How do you measure for a proper ground connection?

**lcaillo** · **02-24-09, 07:07 PM**

Use an DMM and measure ohms.

**robbo266317** · **02-24-09, 07:16 PM**

I would measure for Volts (A.C.) first so you don't blow up your DMM.

**Blktre** · **02-24-09, 08:00 PM**

I'm assuming you check at the coax behind my cable box? Can you explain further please. Thanks again for all the input so far. I want to be armed with some info. before i go to the owner of the company. I'm mad at them for not even being cool enuff to look at it when i pay $180.00/mth for their services....

Thanks again..

EDIT> I'm picking up what your putting down!

**lcaillo** · **02-24-09, 10:39 PM**

http://www.hometheatershack.com/foru...grounding.html

**Blktre** · **02-25-09, 10:03 AM**

lcaillo, well written. Not sure how i missed this on a search. Its eye opening for sure.

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