Electronic signs

I presume these are modern neon signs. If so, they use a solid-state inverter and theoretically are regulated by the FCC. You could try putting a shield around the inverter box, but you would need to exercize great care and caution to keep the shield away from the high voltage exit areas (where the neon tube goes inside the inverter box), as there is tens of thousands of volts. If you do not do it properly, at minimum permenant damage could occur and those inverters run from $100 and up and *must* be EXACT replacements. Alternately, use incandescent lights and there will be no RFI problems.

I'll have to check these out a bit more carefully. IF they're not going to be able to be filtered without damaging the unit, then it may as well be gotten rid of and be done with it. The "radio" system is more important than the sign. I can tell you - the problem doesn't "seem" to be going through the "electrical" system at the moment, as when the "antenna" was disconnected - the problem stopped. The radio could be connected to a 12 VDC battery for testing off the Main Line - but not so easily done. So, at least for the moment, it seems to be emitting the signal via the air. This ought to be interesting to check.

Thanks for the help!

Maybe a safer way is to make a large metal (rectangular) box that surrounds the whole sign, and use flat black painted wire mesh for the side that one looks at / into. That "wire mesh" should be no coarser than chicken wire; the size of those holes determine the lowest frequency that can propagate thru and get radiated. The flat black paint helps greatly to disguize the mesh..

Thanks very much - for the tips. I have spoken to one of the people in charge and did some preliminary testing. While the system isn't totally useless with the interfererence, it is a nuisance - so it has to be cleaned up. But it does allow us time to check out any and all options. I hope to meet with them again this weekend to see what our next step might be.

Thanks