Where can I find instructions to build a device that can block electric/radio transmissions?
If you are trying to block radio interference from some sort of receiver or amplifier, you could try the easy solution of buying a torroidal transformer (made of ferrous material) which is usually in the shape of a donut or a snap-closed assembly. All you need to do is to wrap the power cord several loops around the donut or a square leg of the other. You may find these at Radio Shack, or another electronic parts store. If you are having trouble with an adjacent strong signal, you might be able to build an RF band pass filter that is very sharp. There are some calculations with this approach, but 2 variable capacitors and a home-wound inductor could help you…but this only works if you have access to an antenna. Also, in the vicinity of a transmitter, you could try to sheild your device with tin foil inside the case. Good luck! I fought that stuff for years.
