I just added a powered sub to my system and it has a terrible buzz/hum. The buzz/hum only goes away when I unplug the DISH coax from the wall. Based on responses from a previous post and research, it sounds like my dish might not be grounded properly. What do I need to look for to see if that's the case?
How can I tell if my dish is grounded properly?
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The most significant grounding device should be located outdoors near the point where the cables go into the building. If there isn't such a block or if it isn't connected to anything, then you're not properly grounded.
Are you using a UPS of any kind?
Are you using a UPS of any kind?
That coax grounding block must also be bonded to your main electrical entrance, not just a ground rod or any other convenient grounding point. Sometimes an installer will ground to a nearby piece of equipment like a heat pump outdoor unit. That might be acceptable electrically but it is not by the code. Connection to a copper cold water pipe within 5' of where it enters the earth (with no meter in between) is also acceptable.
It sounds to me like you have a ground loop. That could be due to some funky grounding (or lack of) of your coax system. Is there any chance you could temporarily connect a piece of coax from your sat. cable ground block directly to your receiver? That should help answer that. I also assume your audio system is powered by a grounded AC outlet. Sometimes the house wiring grounds are suspect and any power leakage into the grounds from a faulty piece of equipment could also be a problem. Try running a grounded extension cord from your equipment to other power outlets in your house to see if that makes any difference. If it does, I would call an electrician immediately.
Good luck with it, and do report back...!
It sounds to me like you have a ground loop. That could be due to some funky grounding (or lack of) of your coax system. Is there any chance you could temporarily connect a piece of coax from your sat. cable ground block directly to your receiver? That should help answer that. I also assume your audio system is powered by a grounded AC outlet. Sometimes the house wiring grounds are suspect and any power leakage into the grounds from a faulty piece of equipment could also be a problem. Try running a grounded extension cord from your equipment to other power outlets in your house to see if that makes any difference. If it does, I would call an electrician immediately.
Good luck with it, and do report back...!
Whether or not your system is grounded or not has nothing to do with your subwoofer humm. If anything grounding causes more problems. If I am wrong, I stand corrected.
Check the connection behind the wall, maybe loose.
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I've seen lots of issues corrected (though not the root) by putting one of those adapters on the powerplug of the reciever itself to by pass the ground prong.
Check the connection behind the wall, maybe loose.
Edit:
I've seen lots of issues corrected (though not the root) by putting one of those adapters on the powerplug of the reciever itself to by pass the ground prong.
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Your post is contradicting itself. If you have a ground problem then adding a ground bypass would get rid of the problem. But, in the case of a surge or short, it will create even bigger problems. Having your coax grounded is extremely important.
The problem he is having sounds like a ground loop, which means there are inconsitencies in the ground. I had this problem with connecting a coax from my radio antenna to my radio and then hearing the buzz when I had my radio connected to my computer's audio input jack. I figured out the problem. My house was built in 1952 and there was no ground rod for the house's electrical system.
The satellite dish, and coax need to be connected to a common electrical ground which needs to be connected to the electrical meter and a ground rod near the meter.
So if he has a ground loop problem shouldn't he be calling a master electrician/utility to come and address it? Maybe there is too much resistance in the ground and he needs a 2nd/3rd/4th ground rod installed, I don't know.
More than likely he needs to call the Dish installer and have them properly ground the Dish.
Ok. Call me ignorant to the overall situation. But...here it goes.
So what if it's not grounded properly? Is the fact the system is NOT grounded, is somehow creating the hum the OP seems to be experiencing? How are two correlated???
So what if it's not grounded properly? Is the fact the system is NOT grounded, is somehow creating the hum the OP seems to be experiencing? How are two correlated???
Two items not having the same ground will have a potential (voltage) difference between them which creates the hum. To simplify, if both pieces of equipment are properly grounded they are at 0 volts and no problems. If one is at 0 volts and the other at 2 volts, current will flow causing hum.
Ok. Makes sense 
So in other words, it would be tempting to use a 3-prong to 2-prong electrical adapter with the receiver. Theoretically, that would remove that voltage potential, correct?
So in other words, it would be tempting to use a 3-prong to 2-prong electrical adapter with the receiver. Theoretically, that would remove that voltage potential, correct?
Ok. Makes sense
So in other words, it would be tempting to use a 3-prong to 2-prong electrical adapter with the receiver. Theoretically, that would remove that voltage potential, correct?
You got it.
3-prong adapters
OK, I'm with primetimeguy with everything he said up until this last post. No, no, no, a thousand times no! The 3rd prong is a protective ground and in general removing it will only increase your chances of electrocution! That's why it's there. Don't bypass it unless you actually take that little green wire and screw it vigorously to another well-grounded spot. The real ground is one of the 2 vertical (not D-shaped) prongs on the plug. I have several times seen the true ground come loose, and some equipment will quit working (as it should), while other equipment starts using the protective ground! Were you to disconnect the protective ground in such a situation, in all likelihood the chassis of your equipment would be hot.
I didn't say it was the right thing to do and agree with you. I just agreed that it would be tempting to do what he said.
Ok..Let's say the system is grounded properly. Then what?
There are many differnt opinions on grounding of sat sytems..I go by code..And BTW grounding to an A/C cutoff switch box, electrical raceway(metal and bonded) Cold water copper pipe (provided the system is all copper) electrical outlet or fixture( such as one of those bare bones fixtures one might find in an attic) and opf course the meter base.
Anyway, I have heard from amny private installer sthat they NEVER ground a satellite system. Those people swear they replace more sat receivers that are grounded than not.
Anyway, the hum sounds to me like there may be feedback voltage thru the outlet from the sat receiver....
I have heard of a woman in TN who saw a bolt of lightning emanate from an electrical outlet in her kitchen, travel across the countertop 6 ft, and disappear again into another electrical outlet, causing a fire on the way. I hope it goes without saying that her house was not wired according to code!
I'm with primetimeguy. The OP in all likelihood has a satellite system that is not grounded correctly. But really we don't know that; it could be the ground in the house rather than the satellite dish. Deliberately disconnecting any of the grounds, most especially from rooftop antennas, is quite literally inviting the lightning into your home.
This is wrong !!! The "vertical prongs" are the hot and neutral, the "taller" one, on the left, being the neutral. Neutrals and grounds are bonded in the main panel, but never in any panel remote from the main. Since the neutral is carrying power if a load is connected, it is no longer at "ground" potential at the load end due to the voltage rise that is an inevitable consequence of the resistance loss of the power wire when current is flowing through that wire. A couple of volts above ground is quite common. The ground lead (the "D"-shaped one, by itself), since it generally does NOT carry any amount of power, remains at ground or zero potential. There is current in that ground *ONLY* during a fault condition, which could include a faulty piece of equipment that has some amount of leakage current into the ground path. This is why I suggested that condition in my first response as a possible source for the hum that the OP is trying to eliminate.
Not necesarily. If the neutral comes loose then the equipment connected to that outlet should stop functioning, period! There should NEVER be a situation where power is passing through the ground connections EXCEPT in a fault condition, in which case it is indeed there to protect the living soles who might come in contact from that equipment who might otherwise find themselves a part of the return path. Since the chassis of the equipment is not designed to be part of the power path, it will only be hot in a situation where the equipment itself becomes faulty, e.g., develops a short from a powered portion of the circuitry to the chassis AND the ground connection of the equipment has also been removed. That's the whole purpose of that equipment having a ground connection, and the primary reason why you should NEVER defeat that ground path by using a 3 to 2 prong adapter without giving that adapter a proper ground...
Thank you for correcting my awful terminology. I meant to say "neutral" when I wrote "true ground".
Mistakes like that are what we get when we post while half asleep. The bottom line is still the bottom line: do not defeat the protective ground; it's there for a very good reason.
I know i'm a little late jumping into this conversation.... but just by what i've read so far, i'd guess the satellite system is grounded, and probably better than the house ground. Everytime i've ever had a problem with a floating ground, or ground hum, it was because the outlet that the equipment was plugged in to, wasn't grounded well, and it chose to ground off the satellite system instead.
If it was me, I would move the sub into a different room and try a different outlet, you may find that it is just a loose ground on that outlet, or group of outlets.
If it was me, I would move the sub into a different room and try a different outlet, you may find that it is just a loose ground on that outlet, or group of outlets.
