Horrible AC adapter buzzing - Need help

[contactDX]

Hey guys,

New to the forum but I've been lurking here for a hot minute. Awesome source of knowledge! I encountered this problem today and thought this would be the perfect place to ask for help.

I purchased a Grundig S450DLX this morning from RadioShack and have had a blast listening to stations all over the world. I'm powering from 6 D-Cell batteries at the moment.

The unit came with an AC/DC adapter... Class 2, 120V ~ 60Hz at 9VDC 500mA

When powered with the AC adapter at my friend's house, the radio performs BEAUTIFULLY. It performs exactly the same when using D-Cells as well.

The problem occurs when powering from the AC adapter at MY house. I've tested ALL of my outlets and get the same result... a horrible, very loud buzzing coming from the speakers at all times.

I've come to the conclusion that there's a problem in the wiring of my home and need help trying to find a way to either...

A) Get rid of the buzzing by using some sort of device

B) Trace down the problem and fix it (which would probably require electrical work in my home)


I'm a carpenter by trade, so I'm fairly familiar with how most homes are built but electrical work is not my strongest subject. Can anyone shed some light on what is happening here?

Thanks guys!

 

[nanZor]

If it is just a noisy device on your ac line and you want to try and hunt that down, start by methodically turning off the breakers in the house one at a time and see if you can track the offending device to that circuit.

Aside from that, the DX450 may be indicating an unsafe electrical condition somewhere else. You can do very simple check with consumer grade plug-in outlet testers to make sure that they are wired properly (ground/neutral/hots not reversed, missing, etc). Even if it passes the tests, it only means the wiring is correct, but may still be UNSAFE.

If it isn't just a simple case of a noisy device in the house, but possibly the wiring, then YES HAVE A LICENSED ELECTRICIAN DO AN INSPECTION.

 

[contactDX]

Well for what it's worth, I live in a very rural area. The house was built by two brothers sometime around the summer of '78... long before stringent res building codes and GFCI outlets were the norm. I don't have a single GFCI outlet in my home. Furthemore, 2 outlets fail to work at all (showing 0.0 on my multimeter).*

I tried unpluging all devices, no change. Tried every outlet on my property, no change. Flip breakers while trying different outlets, no change.*

I have the feeling the interference is caused by faulting wiring in my kitchen. Gonna call my buddy who is an electrictian and see if he can help me figure it out.*

The last thing I want is for the house to go up in smoke at 3am.*

 

[wtp]

but first

do you get the buzzing when running on batteries?
it could be something else.

 

[KB7MIB]

Wirelessly posted (Mozilla/5.0 (X11; Linux i686; U; en-US) Gecko/20081217 Vision-Browser/8.1 301x200 LG VN530)

Go to someone else's house and plug the AC adaptor into your radio, then into one of their outlets. If you still get the same buzzing, the adaptor is the issue. Rule that out first. Then track down the problem in your home.

 

[N8IAA]

Wirelessly posted (Mozilla/5.0 (X11; Linux i686; U; en-US) Gecko/20081217 Vision-Browser/8.1 301x200 LG VN530)

Go to someone else's house and plug the AC adaptor into your radio, then into one of their outlets. If you still get the same buzzing, the adaptor is the issue. Rule that out first. Then track down the problem in your home.

Check the fifth line down in the OP's first post.
Larry

 

[KB7MIB]

Wirelessly posted (Mozilla/5.0 (X11; Linux i686; U; en-US) Gecko/20081217 Vision-Browser/8.1 301x200 LG VN530)

Oops. My bad.

 

[wtp]

well....

buy more batteries?

 

[jfhtm350]

What makes you think its in the kitchen? Is that were you had your scanner the whole time plugged in while you were flipping breakers? If that is so, then you need to move your scanner to another room that is on another circuit than the kitchen is and try that. Do you have flourescent light bulbs? I remember someone else traced their noise down to a flourescent bulb.

On another note you may have a bad electrical outlet. If one goes bad and it is not piggybacked then you will loose all outlets that are after the bad outlet in that circuit. You could have your buddy pull the plugin and check the terminals with a multimeter.

 

[737mech]

I'm wondering if maybe it's a TV or PC monitor causing the noise? There are many things that can cause noise.

 

[hightime]

Here are a couple of web sites that might help: FPL | Solving Electrical Interference Problems & RFI Services - RFI Noise locating tips

 

[k3cfc]

Go to the panel box and make sure all of the grounds are secure. this boils down to one thing house wiring.

k3CFC

 

[contactDX]

What makes you think its in the kitchen? Is that were you had your scanner the whole time plugged in while you were flipping breakers? If that is so, then you need to move your scanner to another room that is on another circuit than the kitchen is and try that. Do you have flourescent light bulbs? I remember someone else traced their noise down to a flourescent bulb.

On another note you may have a bad electrical outlet. If one goes bad and it is not piggybacked then you will loose all outlets that are after the bad outlet in that circuit. You could have your buddy pull the plugin and check the terminals with a multimeter.

I actually tried from the kitchen and from the "shack", as well as my bedroom. All results were the same on each pass. I haven't had time to drag my buddy out here to help diagnose (electrician) but I think it's a good idea. He say it's sounds like I've got some sort of wiring fault, probably in the kitchen (due to all the issues we've had with outlets and such in the kitchen).

A ferrite choke did nothing to improve the RF noise on the radio. I have noticed that the noise is ONLY on AM and SW bands. There's nothing at all on FM.

Under AM/SW, the buzzing comes roaring through the speakers at all frequencies. When a STRONG signal is found, you can tune the radio in but the buzzing is still there... albeit very subtle. Obviously for DXing, this is quite annoying.

Someone mentioned the grounds in the panel box.. everything looks OK there. I'm still trying to find the culprit.


NOTE: An FYI, I've noticed that non-OEM Apple chargers for iPhones are EXTREMELY noisy!!! I get wicked amounts of interference from those things! My wife plugged in her phone the other night when I was listening to a station in Shepparton, Australia (10,000 miles!) and it almost blew my eardrums out!

 

[KB7MIB]

Wirelessly posted (Mozilla/5.0 (X11; Linux i686; U; en-US) Gecko/20081217 Vision-Browser/8.1 301x200 LG VN530)

The FM mode at any frequency won't pick up the interference like the AM mode at any frequency will. If you have a scanner that you can switch between AM & FM, start searching at the lowest frequency in the AM mode and go up until the interference is gone.