GSM em-radiation detector LED thingy/bug

• GSM em-radiation detector LED thingy/bug
  Posted by calli on 04 Dec, 2017 18:41
• Hi,
  
  just out of cuoriosity I bough such a "bug": https://www.ebay.de/itm/DIY-Kit-ICSK032A-Mobile-Phone-Signal-Flash-Light-Radiation-Power-New/272780461231
  
  Consists of 9 germanium diodes and a LED.
  
  It does not work. I THINK I put it together the right way. Yes I have a GSM Phone here bt not the faintest light in the LED even while making calls. The LED is working, the diodes are ok with diode tester.
  
  Could it be(e) that my changes for "cosmetic" reasons disturbes? I cut the LEDs legs and also the one diode in front is shorter "legged". The longer "antenneas" I don't know, tested all I could think of with the original ones.
  
   
  
  I also put my Oszi in place where the LED sits, but nothing but that was maybe stupid, I got interesting curves but nothing that changed with the cellphone or my desk lamps in the perimeter.
  
  Cheers,
  Carsten

  ---

  
• #1 Reply
  Posted by Gyro on 04 Dec, 2017 20:39
• Just for reference, those are Silicon diodes, not Germanium, probably 1N4148s.
• #2 Reply
  Posted by calli on 04 Dec, 2017 21:17
• I measured a forward voltage of 0.21V, that was confusing me.
  
  I think it is this:
  http://pdf1.alldatasheet.com/datasheet-pdf/view/83373/HITACHI/1SS86.html
  
  At least not pure Silicon :-)
  
  Carsten
• #3 Reply
  Posted by Gyro on 04 Dec, 2017 21:35
• Ah yes - high frequency Schottky looks very plausible. My mistake.
  
  Personally I'd ditch the detector and make use of the diodes.  Note that they are very ESD sensitive... 30V!
• #4 Reply
  Posted by MasterT on 04 Dec, 2017 21:48
• Probably, it was designed to work on older network, GSM-900 (2G), if your phone ( and network operator - Service Provider) supports manual selection between 2G and 3G, than you can try to register on the 2G and make a call.
• #5 Reply
  Posted by calli on 07 Dec, 2017 15:55
• I have a G2 mobile here. No lights.
  
  Carsten
• #6 Reply
  Posted by jmelson on 07 Dec, 2017 22:40
• Quote from: calli on 07 Dec, 2017 15:55

  I have a G2 mobile here. No lights.
  
  Carsten
  

  Yeah, if a gadget like this ever lights up, throw a chair through the window and run for you life!  The amount of EM radiation it would take to make it light up would indicate you are practically inside an operating microwave oven.
  
  Jon
• #7 Reply
  Posted by calli on 08 Dec, 2017 08:18
• I think it should work.  I guess not all YT videos with theese devices can be fake and lately there was a art project with such devices. And some years ago you could hear the "tac-da-tac-da" of mobiles near a audio amp very often. Yes, G3/G4 is much more silent but therefore I tried with an old (still going) phone.
  
  Carsten
  
• #8 Reply
  Posted by Kalvin on 08 Dec, 2017 13:51
• I wonder why so many diodes. The LED is diode on its own, so it might work even without other diodes. However, if the LED has too much capacitance to work as a decent rectifier (after all, the GSM works around 1GHz - 2GHz), one could add another rectifier diode in series with the LED.