Radio Interference (Static) in brand new home?

Question

I do electrical warranty work for a builder in AZ. I got a call to a home that is having lots of static on their AM radios when any electrical appliance is turned on. It doesn't matter if the radio is plugged in or running off batteries (not connected to the AC). I tried several different radios as well, with the same results.

I understand that ANY electrical device emits certain levels of EMI that may cause static, but even when a small appliance is used on the other side of the house (3500 sq. ft.) - the static is so bad you can't hear anything else over the radio.

I took their radios to the house next door (exact same house, same appliances, same everything) and there is no static at all. Even with the same portable appliances that are giving trouble in the first home.

What would the difference be?

I checked all grounding in the panel (though that's usually more associated with a "hum" not static) and everything looked good.

I would appreciate any thoughts.

Answer 1

The first thing I would look to would be the use of any flourescent fixtures. Those emit a large amount of EMF that will splatter an AM radio station, but will not affect FM. You may also see dingbats go across the screen on all tv channels from Channel 6 down.

Your best tool to check all of this out is a super cheap AM radio - I guess you have already figured this one out. Get a battery operated one and not one that plugs in so that you can attempt to find the offensive connection. Turn the switches on one at a time and see what happens

I would think that somewhere in the circuitry you have a loose connection. I have found often that when this occurs, the installing electrician used push in connectors on the wall switches and plugs and did not screw them in hard. But I would look for a loose screw connection if they are screwed and if they are not, I would change all of them to screw connections. Most electricians are lazy.

Start with the main box, take the lid off of it and look at all the connections, especially the incoming power lines, the feed, to see if thelines are aluminum or copper. If they are AL, check to see if they have NOALOX, or an antioxidant, on them and if they do not, call an electrician and get him to fix that because it requires removal of the meter to kill the whole house power. My house almost burned down because of AL feeds wtihout the antioxidant.

I feel that your problem is either a loose connection or an broken wire where there is a jump from one part to the other.

Check all wall switches and all wall sockets, and well as taking a long screw driver and checking all of the breakers in the box to see if they are tight enough. Look at all overhead lamps, ceiling fixtures, and rewire those making sure that the connections are good.

I would also suggest that if there is a problem on the line, that you take the transistor battery radio, the cheapest you can get, and trot it next to all of the plugs and switches in the house, the box, and even the meter. Walk outside while the radio is popping and see how far you get from the house before it stops. It could be as simple as an arcing transformer outside, but that has to be fixed by the power company.

Answer 2

What i'm able to inform you with actuality is that the interference is 50hz ! ( uk ) or ( 60hz u . s . a . ) meaning the criminal could be something that works on family contributors mains, the acceptable way of finding the source as you have already found out is with an AM radio !. it is exciting that the interference in ordinary terms lasts for 10 or 12 seconds so as that narrows down the opportunities rather !. the 1st that is composed of techniques that I even have had is a badly installation fuse holder in the television set , the fuse holder sparks ( or arcs ) till the warmth generated tightens the holder ! ( fits the ten sec ). A defective starter for a fluro is yet another poss ! A refrigerator thermostat establishing or ultimate is likewise available . i does not suspect the fuse field regardless of the undeniable fact that because of the fact the fuses are often exceptionally tight just to sidestep the subject of arcing ! . There are thousands of different issues that would reason 50hz interference yet do not in superb condition the trend which you describe . it is approximately all i'm able to advise for now . Cheers Pete

Answer 3

The only thing I can think of is bad grounds but, not in all of them, usually if you move one line it fixes it.
Have a master electrician check everything out.

Answer 4

I would look at your main line in. it may be hot, neutral or ground, or more than one. It's the only thing I can think of, I haven't run into that one before.