Noise in the background of my AM radio

[leza wang]

I know this might sound off topic but please read.

I have an AM radio which is plugged into power in the wall. There is a buzz noise in the background of whatever stations I listen to. I turned on one light in the house and all the sudden the noise disappeared. I turned that light off and the noise comes back. The switch of that light is giving scr atching noise when I switch it on/off. So if I keep the light on , I would not hear any noise. Why is that? Is there anything wrong with electrical w iring of the house?

Thanks

[Chuck]

Try changing the switch. Might have dirty contacts. Be sure to turn off main power before changing switch. Safety first!

[Don Phillipson]

1. This noise does not suggest dangerous defects in the house wiring. AM Radio is more vulnerable to interference than FM or digital radio.)
2. Cheap radio receivers are more vulnerable to interference than hi-fi receivers. One common remedy was to reverse polarity of the power plug, i.e. interchange the plug prongs connected to the power wire.
3. Chuck probably meant you should inspect the wall switch that silences the AM interference. At least, without touching, you could remove the face plate and see whether any wire is loose. (Nudge each wire with a wooden pencil -- not a metal conductor.) If you see any sign of malfunction, switch off the (fusebox) breaker controlling this switch and tighten all connections with a screwdriver (or else call an electrician.).

[BenignBodger]

Dimmer switch or regular? What sort of bulb is in the fixture? Are you in a weak-signal area? My mother used to live in an area where the AM signals were always weak from every station, even a 50kW station less than 20 miles away, and it seemed that everything vaguely electrical in the neighborhood caused noises to come and go.

[Tony Hwang]

Hi, If so, remove the switch and take a look. Loose connection, maybe. Or wall switch is cheap just replace it and report back. My AM radio is NRD pro grade receiver I seldom use. It has noise blanker which is pretty effective.

[J Burns]

If the switch were good, I'd wonder if was illuminated. Household switches with neon pilot lights became available 60 years ago and could probably interfere with an AM radio.

If the switch is scratchy, I'd replace it.

[Ed Pawlowski]

the noise occurs when the switch is off. Goes away when it is on. How would the contact affect that?

[gregz]

That not an unusual circumstance. Any change in wiring conduction can cause antenna effects.

You can try unscrewing the light. If there is a problem with that circuit, that might indicate something. Or, unplug the light.

Greg

[micky]

The suggestion about the illuminated switch is important, because that little light is on when the switch is off. Many of the other suggestions seemed mostly to apply if the radio worked badly when the switch was on. Still, changing the switch is one obvious thing to do. Maybe there is a carbon trace inside the switch that allows a little bit of current to flow, erratically.

I have a 200 dollar table radio that, when the VCR right next to it is on, it interferes with the radio's sound. Of course there is no real need to have a play-only VCR on when the radio is on, so I can just turn it off.

[Fake ID]

I don't know why. But I'll add an anecdote. Sometimes there is loud background noise on AM recption. It disappears while the microwave xor the toaster over are running. Both appliances are on the same outlet across the house fro where the radio is plugged in. Eventually the noise disappears "on it's own".

So, in conclusion, it's not the switch, it's the power consumption.

m

[Ed Pawlowski]

What would that do? The light on FIXES the problem, not causes it.

[Pat]

Everyone seems to be guessing, so here is my guess - Some nearby device in your house is creating the noise on your power lines. It could be a TV, a florescent light, a plugin power supply for a cell phone or some other device, a computer, or practically anything. When you turn on the light controlled by the switch, that load drowns out the noise. If I am correct, there is no danger or problem with your house wiring. You just need to find the device creating the noise and unplug it or filter it. Try turning the switch on and then unscrewing the bulb in the light it controls. If the noise returns, it supports my theory that the electrical noise is being lowered by the load controlled by the switch and there is nothing wrong with the switch or wiring. Good luck.

Pat