2.4Ghz field strength meter

strength

This is a really simple way to measure WiFi strength. Actually, it will measure anything in the 2.4Ghz range, like your microwave. The device consists of a two element quad antenna, a Ghz sensitive diode and a variable capacitor for tuning. The sensor is plugged into a voltmeter for measurement. The page has links for locating the specialized diodes.

Comments

  1. joelanders says:

    this thing is cool. i wonder if he could build three of them and pinpoint the source of the emr. like if they were spaced out enough and he had some software that interprets the differences in strength…. bah maybe too complicated…

  2. winphreak says:

    That idea’s not bad. It’s how they pimpoint earthquakes. Only difference is funding.

    And I wonder how an old microwave would register on that thing.

  3. burndup says:

    ARRRGH! He doesnt specify EXACTLY which diode he used… I have a box full of thrift-store radar detectors and other door-opener gunnplexers, (all have SIMILAR microwave diodes in them) but theres no way to tell which will work best…

  4. tns says:

    This is a beautiful hack. Thanks, Eliot.

  5. John Bokma says:

    Forwarded this to my brother, he probably will be happy with it :-D

  6. ez says:

    Teamhackaday.com is down, right when I was about to submit a long post too.
    :(

  7. ez says:

    Nevermind, it’s up,

  8. Jkx says:

    The main issue, is that this kind of diode are really rare, and hard to find. So don’t dream to much about this.

    ByeBye

  9. PEte says:

    HELLO, MY NAME IS PETER AND I LOVE ROSE. I HAVE BEEN MADLY IN LOVE WITH HER SINCE KINDERGARDEN AND I CANT WAIT TO SEE HER AGAIN. SMOOCHY SMOOCH ROSE. I LOVE YOU. KISSY KISS ROSE. I LOVE YOU. WOOOOOOOOOOOOWOOOOOOOOOOOOOO PIPIT. I LOVE ROSE.

  10. rc:line says:

    1N5711 schottky diodes will work, and are much easier to find. To drive an analog meter, you’d need to buffer the diode’s output with an op-amp. For a accurate reading in dBm, look into the Analog Devices AD8313/AD8314 series of log detectors.

  11. monster says:

    10 bucks says petes a virgin

  12. D. Cooper says:

    Another good source for these microwave diodes is old radar detectors. Nearly any radar detector that uses a cast metal waveguide horn and mixer housing will have one or more detector diodes installed in their mixer stage.

    Some manufactures of radar detectors used “strip-line” waveguides and mixers, so these will have a double-sided p.c. board with
    tiny little “pellet”, surface-mounted diodes instead of a 3-dimesional “horn” assembly. These would, admittedly be much harder to de-solder/solder to without overheating and destroying them, but might make for a far more compact antenna assembly.

    Standard ESD precautions should also be observed to protect these types of diode/s from static discharge while handling and soldering.

    DC

  13. Bob says:

    Ugly, but beautiful! I’m wondering if the guage of the copper wire makes a difference? It looks as though this person used a 12 guage wire for the elements. This would maybe make a good detector for tooling around the neighborhood in your car, seeing which neighbors of yours are using an 802.11g transmitter ;). Oh – and put me in for 10 on pete also.

  14. Bob says:

    Ugly, but beautiful! I’m wondering if the guage of the copper wire makes a difference? It looks as though this person used a 12 guage wire for the elements. This would maybe make a good detector for tooling around the neighborhood in your car, seeing which neighbors of yours are using an 802.11g transmitter ;). Oh – and put me in for 10 on pete also.

  15. burndup says:

    Mixer diode outta the radar detector, eh?

    Ima slap one of these puppies together tonight!

  16. Jan kåre vatne says:

    Look at http://www.farnell.com/datasheets/27736.pdf for a more professional detector. The diode is quite cheap by the way – only ca $3. Its name is HSMS-286K. Get it at Farnell: http://no.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=3883103&N=401

    jkvatne

  17. Jeffrey says:

    i just recently took apart my old Gameboy Color and noticed that at the top of it there are a couple of LED’s. i was just wondering if the Gameboy Color was originally meant to be able to control things remotely with its LED’s.

  18. n0lkk says:

    Argh; led here by a current post, but I don’t see s link to project, but found this when trying to find it http://www.qsl.net/n9zia/wireless/appendixF.html Which may or may not be useful with anyone plating with microwave RF.

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