And I'm saying I have neither basement or crawlspace. I have a concrete slab on the ground. I do not have access to my water main.
HR21, grounding and SW hum
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And I'm saying I have neither basement or crawlspace. I have a concrete slab on the ground. I do not have access to my water main.
AC power from phone ground?
Checking with my meter, I find that the ground for the phone system is putting around 1 volt A/C into the ground. If I remove the phone ground, the hum goes away. Naturally I replaced the phone ground after this brief test.
Is 1 volt A/C normal coming from the phone ground?
Checking with my meter, I find that the ground for the phone system is putting around 1 volt A/C into the ground. If I remove the phone ground, the hum goes away. Naturally I replaced the phone ground after this brief test.
Is 1 volt A/C normal coming from the phone ground?
This sounds like the house I had before I moved. Classic slab with a copper pipe coming up through the floor in the "utility" "room" (it was actually a closet behind the kitchen). When I first set up my new outdoor TV antenna and grounded it via a 6' copper rod pounded into the ground by the ground block, it was hum city. This all predated Google and web browsers, so it was off to the library for help.
I had to bound the ground rod at the electrical service to the 2nd ground rod with some 8 gauge copper cable. This knocked out the majority of the hum, but it then pointed out the problem of having duplex outlets in a house built in the 1950s. After running grounded 14-2 romex to the AV center, I finally had a low-impedance ground between the TV and my stereo.
While I was bounding grounds, I also ran 8 gauge from the fuse box to the copper water pipe where it came up through the floor. I used emery cloth to clean a section of the pipe and attached the ground clamp.
Good luck eliminating the hum monster!
I had to bound the ground rod at the electrical service to the 2nd ground rod with some 8 gauge copper cable. This knocked out the majority of the hum, but it then pointed out the problem of having duplex outlets in a house built in the 1950s. After running grounded 14-2 romex to the AV center, I finally had a low-impedance ground between the TV and my stereo.
While I was bounding grounds, I also ran 8 gauge from the fuse box to the copper water pipe where it came up through the floor. I used emery cloth to clean a section of the pipe and attached the ground clamp.
No, it isn't. But the small amount of current from the phone ground should not lift your house ground enough to cause hum. That points to an inadequate electrical ground (IMHO). I would try measuring between the house ground and the cold water pipe before it goes into your water meter. I'm curious what the potential there is.
Good luck eliminating the hum monster!
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Okay, this is the first time you have mentioned being on a slab. The water has to come into the house somewhere, yes? Is the water feed a copper pipe? If so, can you get to it? If so, try connecting a wire from the dish to the water pipe and see what happens. This isn't rocket science.
Chip, many houses out west that are on slabs have no cold water pipes that are accessible except at the meter by the street. Some will have a shut off next to the house, but more often than not the shut off is at the meter. The run from the meter to the house is PVC, so it can't be used as a ground anyway! A proper cold water pipe ground will also be attached to the house bond, so it won't make any difference with the ground loop. DirecTV isn't allowing dishes to be grounded on the cold water pipe anymore.
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Does your stereo receiver have a ground lug? Many do, check your owners manual. You can run a #16 wire from the ground lug to the center screw on an outlet. That will often times remove the ground loop.
How old is your house? Do you have three pronged plugs at the outlets?
Are your familiar with electrical wiring at all? A ground loop can be caused by a neutral wire and a ground wire on the same bus. Inside your electrical panel you will see two screw terminals. One is for the neutral wires (white) and one is for the grounds (bare copper or green). If a neutral wire is on the ground bus and or a ground on the neutral, everything will work fine, but you will get hum like you described. The circuit your HR21 is on could have the ground or neutral on the wrong bus.
How old is your house? Do you have three pronged plugs at the outlets?
Are your familiar with electrical wiring at all? A ground loop can be caused by a neutral wire and a ground wire on the same bus. Inside your electrical panel you will see two screw terminals. One is for the neutral wires (white) and one is for the grounds (bare copper or green). If a neutral wire is on the ground bus and or a ground on the neutral, everything will work fine, but you will get hum like you described. The circuit your HR21 is on could have the ground or neutral on the wrong bus.
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This is exactly the case with my house. The water main is PVC. The shut off is at the meter, about 15 feet from the house. One of the copper pipes for a hose connection has a wire connected to the house ground rod.
The ground lug reminded me of a post I found from a Google search in which the OP suggested running a coax from the FM antenna connection of the receiver to the power strip connection. I just tried that and it reduced the level of hum by about 50%.
I'll have to pull the receiver out to get to the ground lug, so I thought I'd try the coax first. Tomorrow I'll try the ground lug.
Hey, 50% is progress!
I'll have to pull the receiver out to get to the ground lug, so I thought I'd try the coax first. Tomorrow I'll try the ground lug.
Hey, 50% is progress!
Okay, if you had mentioned that when I first suggested using the water line for the ground, we both would have saved a lot of trouble.
Another day, another result
I attached a ground from the back of the receiver to the outlet cover screw. I also tried attaching directly to the wire on the green post of the outlet.
The ground reduced the hum about the same as when I have the FM antenna routed through the power strip.
If I have both ground and FM antenna in place, the hum is reduced to the lowest level yet but is still quite audiable.
I also noted that the hum is louder with the receiver powered on then when it is off.
I attached a ground from the back of the receiver to the outlet cover screw. I also tried attaching directly to the wire on the green post of the outlet.
The ground reduced the hum about the same as when I have the FM antenna routed through the power strip.
If I have both ground and FM antenna in place, the hum is reduced to the lowest level yet but is still quite audiable.
I also noted that the hum is louder with the receiver powered on then when it is off.
Did you see my other post about neutral and ground wires combined in your panel? It's a common problem with ground loops.
Okay, let's go back to your first post. You said the hum started when you connected hdmi cables from your a/v receiver to the other components, yes? Did you have any hum before? Have you tried going back to the component cables to see if the hum goes away? Did you find a ground on the subwoofer and did you try grounding it? How about removing one hdmi cable at a time to see if that removes the hum. Also, you could try running a ground from the a/v receiver to the sub if the sub has a ground on it. Keep at it, you'll figure it out!
I've tried some things -- I'll try again, making sure to check these items now that I have the receiver itself grounded.
I opened up my breaker panel. All the whites are on one side and all the cooper is on the other. I noticed that the cooper is twisted together in groups when connected. I wonder if that's left a wire not well connected.
The SW doesn't have a ground. I went through the other suggestions -- nothing helped.
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