Thread: EMF detector diagrams?

hi,

wonder if any of you got working EMF detectors... really would love to build one.... to see if my room has any "hidden" radiation... :)

You should use the following sequence: wire antenna, broad band RF amplifier, diode detector, indicating method.

A simpler method which is not as sensitive is the wire, diode, oscilloscope.

could you maybe post a diagram?? :) particularly that broad band RF amp...

Here is a link to a field strength meter http://www.alphalink.com.au/~parkerp/noapr97.htm

If you are looking for hidden espionage devices you do a raster scan moving this instrument across the surface of the walls, floor, and ceiling of your room. Then over all of the surfaces of the objects in the room. This still will not get all of the devices because they can be remotely controlled to turn on and off to save battery power.

If you do a google search for 'field strength meter' you will get at the top of the list hobby grade ones with low cost.

are field strength meter and EMF meter, the same?? i mean do they operate the same principle? :)

They are different words for much the same thing. Field strength meters used in industry are calibrated for strength in volts/meter. Since all you want to do is discover espionage bugs, knowing the exact stength is not necessary.

Originally Posted by flatulent

They are different words for much the same thing. Field strength meters used in industry are calibrated for strength in volts/meter. Since all you want to do is discover espionage bugs, knowing the exact stength is not necessary.

hi, im not looking for espionage devices... what im trying to "see" is electromagnetic feild around me :) ....around my room actually.... ex. electric FAN, TV, any other AC operated devices.... to see if they emmit electromagnetic or magnetic radiation.. that is at a level too high....

At these low frequencies you can make a series circuit of a coil, diode, and current meter.

Originally Posted by flatulent

At these low frequencies you can make a series circuit of a coil, diode, and current meter.

low frequency meaning 50/60Hz magnetics?? :)