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I have a sound system for the TV that's approx. 20 years old which is clustered with wireless router. I updated the router recently and now I'm getting interference thru the subwoofer that sounds like a very soft machine gun - a popping sound about 500 beats/minute. If I turn off the router, the sound goes away. If I move it about 6 feet away the sound also goes away. Both are plugged into the same wall outlet. The simple solution is to find another permanent place for the router, but unfortunately the service it's hooked to dictates that it goes there unless I want to take on a large wiring project.

 

Is the common electrical outlet the problem? I didn't have this problem with the old router. Is there a way of shielding the subwoofer & router from each other? 

 

Thanks for your help!

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Maybe put them on 2 different power strips?

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Are your plugs polarized/keyed so that it can only go into the receptacle one way? If not, you might try reversing it.

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I just plugged my tester into the outlet and it shows an open ground. An outlet on a joining wall, which I'm pretty sure is on the same run, shows the same. Next is the pulling the outlet to see if there's actually a ground hooked to anything. This house was built in 1959 and it's possible someone put a three wire outlet on a two-wire circuit.

 

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7 minutes ago, Abilene Slim SASS 81783 said:

I just plugged my tester into the outlet and it shows an open ground. An outlet on a joining wall, which I'm pretty sure is on the same run, shows the same. Next is the pulling the outlet to see if there's actually a ground hooked to anything. This house was built in 1959 and it's possible someone put a three wire outlet on a two-wire circuit.

 

What you just described is common. If the circuit is protected by a GFCI, the use of three-prong outlets is acceptable. If not, it's a NEC violation. But, it also means if you're using a grounding plug, interference can't be shunted away to ground. Wiring in 1959 is going to be iffy with having a ground. Our first house. built in the early 1960s, had a ground in the cable but the original electrician didn't connect it to anything.

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Thanks Cholla and Sue. It's a 2-wire circuit. Now the challenge is running a ground wire which is going to involve some wall demo between the outlet and floor. Below is the basement and something to hook it to. 

 

In the meantime, will an open ground produce the interference described?

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My 1960 house is entirely two-wire.
When I installed 200 amp service, it got an 8' grounding rod driven into the ground below the panel.
The electrician wired the old 90 amp panel as a sub panel to the new main, and it is now grounded.
Existing circuits on the old panel are still two-wire, but the new kitchen circuits, etc, are proper three wire.

Glad to see you use a tester.
I carry one in my music kit... every outlet is tested before the band plugs in.

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1 hour ago, Abilene Slim SASS 81783 said:

I just plugged my tester into the outlet and it shows an open ground. An outlet on a joining wall, which I'm pretty sure is on the same run, shows the same. Next is the pulling the outlet to see if there's actually a ground hooked to anything. This house was built in 1959 and it's possible someone put a three wire outlet on a two-wire circuit.

 

That isn't a cheap thing to fix, without running wiring conduit strips outside the wall, under baseboards, etc. 

 It is actually quite a dangerous condition.

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2 hours ago, Abilene Slim SASS 81783 said:

I just plugged my tester into the outlet and it shows an open ground. An outlet on a joining wall, which I'm pretty sure is on the same run, shows the same. Next is the pulling the outlet to see if there's actually a ground hooked to anything. This house was built in 1959 and it's possible someone put a three wire outlet on a two-wire circuit.

 

Shanley is here shaking his head "yes".

 

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1 minute ago, Singin' Sue 71615 said:

Shanley is here shaking his head "yes".

 

Says you may have lost your 'earth ground'.

Spoke on what Bgavin said.

 

Daddy built the cabin in 1962.

He was the GC...

The main two lights were on a 3 way (switch on either end by doors, worked both lights)

Oh My WORD!!! You would not believe what we had to do to put two ceiling fan lights in the same spots!!!

Eeek...new ways/new codes/ new tech

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3 hours ago, Abilene Slim SASS 81783 said:

Thanks Cholla and Sue. It's a 2-wire circuit. Now the challenge is running a ground wire which is going to involve some wall demo between the outlet and floor. Below is the basement and something to hook it to. 

 

In the meantime, will an open ground produce the interference described?

The short answer is yes. My wife used to sing in a band and I used to play guitar just for fun. Many places we played had not great electrical systems and fluorescent lights, which cause considerable noise on the line. I got tired of it and since I had the means, I made an 1.5 KVA isolation transformer that separated the common/neutral from ground, so that the power in no way was connected to ground. It worked beautifully and took all the buzz out of the equipment. I also wired a recording studio many years ago and did a ton of research before hand. In it I ran everything in conduit and used hospital grade isolated ground receptacles so that the ground was separate from the conduit (if I remember right). That all went back to a panel where I kept all the grounds separate from the neutrals. The studio was quiet and my wife got 160 hours of recording time in exchange, of which half never got used but that's a scab I prefer not to pick 23 years later.

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Yes. 

 

Shanley says " the old tech items did not care if they got a 'little mud on their face'...they muddled through. The new tech are prissy little things that "don't want to get their hands dirty".

That is why you did not have the issue BEFORE upgrading the 'new' router.

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Before you go through the trouble of getting a ground to the router/equipment, run an extension cord to a receptacle with a known good ground. Use your tester to make sure that the receptacle used has a good and as well as the extension cord. Plug your equipment into the cord and see if the problem goes away. I'm betting on the problem resulting as the lack of a good ground also.

 

Please be aware that installing a ground wire that is not integral with the circuit that controls the receptacle does not comply with NEC and could create other, possibly dangerous, situations. 

 

If your house was built in 1959, I seriously doubt that there is a ground wire within the wiring cable. If there is a ground wire in the cable, it will be a smaller bare copper wire. That wire was supposed to ground the metal box that the receptacle is in. Like Cholla, I've found where the original electrician did not connect the ground wire to anything and in some instances, didn't even twist the wire together to continue the ground path.

 

If it is possible, I suggest installing a new 15 amp (14 gauge wire) or a new 20 amp (12 gauge wire) to the equipment and install a new receptacle. 

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6 hours ago, Abilene Slim SASS 81783 said:

Thanks Cholla and Sue. It's a 2-wire circuit. Now the challenge is running a ground wire which is going to involve some wall demo between the outlet and floor. Below is the basement and something to hook it to. 

 

In the meantime, will an open ground produce the interference described?

There are a number of ways to add grounding conductors to old work with minimal destruction of preexisting walls.  It's pretty easy  to fish the single conductors up or down inside the wall, if you have an accessible attic or under-floor crawl space.  

 

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On 2/4/2022 at 10:59 PM, Cypress Sun said:

Before you go through the trouble of getting a ground to the router/equipment, run an extension cord to a receptacle with a known good ground. Use your tester to make sure that the receptacle used has a good and as well as the extension cord. Plug your equipment into the cord and see if the problem goes away. I'm betting on the problem resulting as the lack of a good ground also.

 

 

 

THIS ^^^ 

When I have a proper keyboard I'll provide a more details. 

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19 hours ago, Sedalia Dave said:

 

THIS ^^^ 

When I have a proper keyboard I'll provide a more details. 

 

Definitely plug the router into another outlet using an extension cord to see if this makes a difference. Be sure that the cord to the router is in as close to the same position as it would be if it was plugged into the wall.

 

What you are most likely experiencing is RF interference from the switching power supply in your new router. Seems that manufacturers are getting pretty sloppy with their designs and the latest crop of switching power supplies tend to generate a lot of Radio Frequency Interference (RFI)

 

I guess the first question is your sub woofer wired or wireless?

Is the part of the new router that plugs into the wall a straight plug or is it a little black square/rectangle? If it is a straight plug is there a rectangular box in between the plug and where it connects to the router?

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5 hours ago, Sedalia Dave said:

 

Definitely plug the router into another outlet using an extension cord to see if this makes a difference. Be sure that the cord to the router is in as close to the same position as it would be if it was plugged into the wall.

 

What you are most likely experiencing is RF interference from the switching power supply in your new router. Seems that manufacturers are getting pretty sloppy with their designs and the latest crop of switching power supplies tend to generate a lot of Radio Frequency Interference (RFI)

 

I guess the first question is your sub woofer wired or wireless?

Is the part of the new router that plugs into the wall a straight plug or is it a little black square/rectangle? If it is a straight plug is there a rectangular box in between the plug and where it connects to the router?

Wired SW

Little black square plug directly into wall

 

router plug into wall, SW into power strip that plugs into same outlet 
 

will let you know how grounded extension cord test works. 
 

thx!

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