I've got a house that sits directly below a huge radio tower on the top of a mountain. The radio station plays through the sub when NOTHING is plugged into it. A velodyne sub had to be pulled out and replaced with an Energy sub which was less susceptible to the noise. Carefully laying the cord the right way and wrapping it in foil tape minimized it to an acceptable level to the client.

The radio station leaks into the computer speakers... a problem I've yet to fix.

The most annoying problem is the VCR to Yamaha LPX500 projector. It tunes in stations and sends an acceptable picture to the projector over both Composite or S-video. Play a tape and the unit is taken over by red, green and blue video noise that renders the picture unwatchable. Grab the cord and scrunch it up and the radio station plays through the VCRs audio.

Yamaha told me that this was a common problem with this projector because they designed it to work with higher resolution sources. I said what?????

I took the latest VCR (we've used six different brands... all of us bringing one from home) down to the Good Guys where the projector was purchased, hooked it up to their display unit and it played a tape just fine. They gave me their projector for the customers and when I took the unit that had performed well in the store to the harsh environment... the same thing happened. We can minmize the noise by placing our hand on the VCR and standing next to it but obviously this might prove a little cumbersome!

Now that we have determined that the problem is environmental... where do we go? Anyone ever dealt with this? The customer may accept it and just not play video tapes in his theater as DVDs and HD Sat Rcvr look good. I just hate leaving something like this without exhausting every possible avenue.

Get on the phone and talk to the station engineer. The FCC mandates that broadcasters have to be good neighbors, and they will help.

I had a radio station buy 6 square blocks worth of radios to help overcome a problem they had.

Often, strong RF is fed into equipment via the interconnects. Even speaker wires can feed RF into an amps output devices, where the diode effect of the transistors can 'detect' (rectify) the RF signal, and output audio.

Snap-on ferrite cores can do a lot to alleviate the unwanted signals. They should be applied to cables as close to the equipment ends of the cables as possible, and a second turn of the cable through the ferrite can improve the effect.

Larry
www.fineelectricco.com

What about a Faraday cage around the vcr and projector?

That's a good one!

Wouldn't this likely cause a bit of "screen door" if the entire room and the screen itself were not inside the Faraday cage? Or worse yet, unacceptably low white levels due to the Faraday cage not allowing high frequencies (light) to pass through its walls?

I would just build the cage around my entire home. To eliminate any future possible issues.

No, you guys! The thread was called:

"Another crazy problem... any ideas?"

...not "Another problem... any crazy ideas?"

The Faraday cage is a good idea, but the equipment casings, so long as they are metal, is a good enough shield. The trouble is in the wiring, almost certainly.

Maybe you could use quad RG6 in conjunction with the ferrite devices? You could try not terminating the outer shield of the RG6?

The Yamaha is likely a hot chassis, but I don't know about the VCR. Maybe you could use the center conductor in the RG6 cable without anything else connected and run a separate RG6 center conductor under a screw on both devices? If the chassis are not hot on either/both device(s), you could connect the center conductor from the RG6 to an obvious ground on one of the circuit boards (after the power supply primary.)You could add the ferrite thingies too.

I'm no expert on this sort of problem, but that is what I'd try.


Dispose of the radio station:
[Link: answersingenesis.org]

Could you have a small ground differential? This would allow the ingress. It would likely be charactorized with some hum in addition to the radio station.

Fred harding said

"Get on the phone and talk to the station engineer. The FCC mandates that broadcasters have to be good neighbors, and they will help"

Larry Fine said

"Snap-on ferrite cores can do a lot to alleviate the unwanted signals. They should be applied to cables as close to the equipment ends of the cables as possible, and a second turn of the cable through the ferrite can improve the effect".

Those are both great ideas. You have a really bad situation where you are. It's also possible that all of these symptoms are being caused by just one component in the house. start unplugging things one by one.

have you talked to any of your neigbors to find out if they have similar problems?