7 replies to this topic

[Memelz33]

Fellow fans of the new fictional based tv show, 'Supernatural' might have seen the episode a few weeks ago where Dean was using what he said was a homemade EMF meter that he made out of a busted walkman--this totally facinated me, and I have been trying to find out if that is possible to actually do and try to make one myself, but i have been unable to locate ANY info on how to make homemade EMF meters anywhere on the web.....Since the show IS fiction, then i figured theres a good chance that that may be fiction too, right....lol. . but, i keep thinking that it should be possible--just not sure how to go about it...anyone have a clue, and if so, then anyone know exactly what id need to have/do to make one?? Thanks guys!

[Crosis]

Yes it is possible to build your own emf meters but it is not atall easy.. . In our group we have two members that are qualified radio amateurs (i am one of them) and three of us have a background in electronics design, prototyping and electronics test engineering and we are struggling to build an effective sensor and pc interface.. . Calibration of the device and making it sensetive to the frequency range we need is the most difficult part. We are trying to build a wide frequency sensor that ignores fields created by house wiring (50hz UK and i think 60hz USA). . . We can build them with different frequency ranges that are selectable but we are trying to make it idiot proof.. . the thought that someone has made an emf meter from an old walkman makes me shudder, surely that would be wildly inacurate.. . If you just want a basic meter your better off buy one that will be calibrated. but if youy do find a circuit diagram or instructions i would be very interested in seeing it

[Memelz33]

"the thought that someone has made an emf meter from an old walkman makes me shudder, surely that would be wildly inacurate". . ----Deans homemade EMF pinpointed that nasty old demon entity with nooooooo problem!! lmao!!!! Yeah, i had a feeling that was prolly too easy to be true sounding LOL I appreciate that info and if i do happen to come across a diagram or instructions, you can bet ill bring it right back here!

[Zeus]

Oh The Humanity!

[rbiermann]

Yes it is possible to build your own emf meters but it is not atall easy...In our group we have two members that are qualified radio amateurs (i am one of them) and three of us have a background in electronics design, prototyping and electronics test engineering and we are struggling to build an effective sensor and pc interface...Calibration of the device and making it sensetive to the frequency range we need is the most difficult part. We are trying to build a wide frequency sensor that ignores fields created by house wiring (50hz UK and i think 60hz USA). ..We can build them with different frequency ranges that are selectable but we are trying to make it idiot proof...the thought that someone has made an emf meter from an old walkman makes me shudder, surely that would be wildly inacurate...If you just want a basic meter your better off buy one that will be calibrated. but if youy do find a circuit diagram or instructions i would be very interested in seeing it

.I don't know if this will help you, but there is a DIY emf kit. here are details found at http://www.lessemf.com/kits.html :..TRI-FIELD METER KIT.Build Your Own Multi-Purpose Meter ..Three separate field sensors to provide a really cool readout on two Sci-Fi styled LED bar graphs! Utilizing the latest technology, including Hall Effect sensors, you can walk around your house and actually "SEE" these fields around you! Can detect the magnetic field of the earth...THAT'S sensitive! Also detect radiation from monitors, TV's, electrical discharge, and RF emissions. You will have fun finding these fields and at the same time learn the technology behind them. ..Three position selector switch that lets you select which type of field you want to detect: either RF, DC magnetic, or electric. Display consists of two LED bargraphs, one at the top and one at the bottom. These indicate the relative strength of the field you are detecting. All in all, it’s a great way to learn about the use of electronic components as sensors and own a little piece of sci-fi at the same time. A great teaching tool for kids of all ages; show them the invisible fields all around them and learn about electronic circuitry and soldering. ..Detect RF from your radio transmitter, computer monitor, or cell phone. .Pick up the field from magnets around your house, even the earth! .“See” the charge on a staticly charged hairbrush or comb. .Learn how to use electronic parts as sensors. .Sense different magnetic poles! .Runs on 4 AAA batteries, not included. .Small, handy size for portability. .Fun LED displays. .Single Axis

[....]

Thats a really interesting find rebiermann, I would like to use one of these sensors.

[Ebonrook]

the thought that someone has made an emf meter from an old walkman makes me shudder, surely that would be wildly inacurate...

.I got the impression from the show, and my own idea, that it was just the plastic shell of the walkman that he was using. Plus headphones for audio output seemed pretty nifty..I don't think he literally built it out of the parts of the walkman (or at least only). He isn't Macgyver after all...I personally think the easiest way to get the walkman one is to buy a reasonably priced EMF meter, take the plastic shell off of it, and place the electronics into the walkman. Should be effective ^^

[kenwhite23]

RF Sniffer <.5 to >500 MHz.. By J.L. 10-94. . . +----+-----------+----------------+-------+ . A N T + | | | | | . ________ 22 --- | | | | P.B. . \ | / uF --- | | | o SW 1 . \|/ | | | Q2 PNP | \ . | --- | / 2N | o \ . | L1 GND | R5 \ 2907 | | . | 4.7uH | 10K / | | . +--()()()-+--/\/\/\--)--+ \ R6 E / --- . | | R3 4.7K | | Q1 NPN | 4.7K |/ = B1 . | D1 --- | | 2N +---/\/\/\---| --- 9VDC . --- 1N270 --- C3 | | 3904 | |\ = . ^ Ge | .01 / | / \ | . | --- uF R4 \ | |/ | +---+ . | GND 22K / +----| +----+------+ | . | \ |\ | | | . +-----+--/\/\/\-+ | E \ \ | | . | | R1 2.2K | | | / R7 ====== | . --- --- | \ --- \ 1K | BZ1| | . --- --- +--->/ GND / | ~~ | | . | C1 | C2 R2 \ | ====== | . | .001| .01uF 10K | V LED1 | | . ------+--------------+ --- >>> | | . | | | | . --- +-----+-----+-----+ . GND | . --- . GND .LEGEND: + = Connection. ) = No Connection. GND = Ground. . . Parts List. .ANT = Radio Shack Cat No. ? to fit project. 24 inches or so long..B1 = Battery, 9 volt transistor radio, clip-on terminals, and mounting brkt..BZ1 = Radio Shack Cat No. 273-074.C1 = .01 uF ceramic, 50V or higher.C2 = .001 uF ceramic, 50V or higher.C3 = .01 uF ceramic, 50V or higher.D1 = 1N270, 1N34A, or other Germanium signal diode..L1 = 4.7 uH RF Choke.LED = RED LED Flashing LEDs don't need R7, and will reduce battery drain. considerably. It has to be a red LED for warning! No? Well...Q1 = 2N3904 or other NPN high gain gen'l purpose, such as PN2222A, etc..Q2 = 2N2907 or other PNP high gain gen'l purpose, such as 2N3906, etc.. .All resistors are 1/4 Watt unless otherwise stated..R1 = 2.2K 5%.R2 = 10K trimmer pot, PCB mount.R3 = 4.7K 5%.R4 = 22K 5%.R5 = 10K 5%.R6 = 4.7K 5%.R7 = 1K 5% or to suit LED brightness and battery drain. Minimum 470 ohms,. except if you use a blinking LED with built-in current limiting..SW1 = Switch, SPST (single pole, single throw) push button to save bat-. teries. Miniature preferred.. .MISC: Case, plastic.. PC board to mount components on (R-S cat no. 276-148 is ok).. Hookup wire, 24 gauge.. .Note: Keep diode and capacitor leads short to minimize stray inductance.. . .Comments: This circuit isn't very sensitive, and could use a good .wideband RF amp between the antenna and the detector diode...--- Cut Here ---..--.=====================================================================.| John Lundgren - Elec Tech - Info Tech Svcs | Standard |.| Rancho Santiago Community College District | disclaim- |.| 17th St. at Bristol \ Santa Ana, CA 92706 | ers apply.|.| jlundgre@pop.rancho.cc.ca.us\jlundgr@eis.calstate.edu | |..totally didnt post right heres a link My link

Edited by kenwhite23, 16 May 2012 - 09:53 PM.