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Electronics => Beginners => Topic started by: calli on December 04, 2017, 06:41:51 pm

Title: GSM em-radiation detector LED thingy/bug
Post by: calli on December 04, 2017, 06:41:51 pm
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 (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
Title: Re: GSM em-radiation detector LED thingy/bug
Post by: Gyro on December 04, 2017, 08:39:08 pm
Just for reference, those are Silicon diodes, not Germanium, probably 1N4148s.
Title: Re: GSM em-radiation detector LED thingy/bug
Post by: calli on December 04, 2017, 09:17:05 pm
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 (http://pdf1.alldatasheet.com/datasheet-pdf/view/83373/HITACHI/1SS86.html)

At least not pure Silicon :-)

Carsten
Title: Re: GSM em-radiation detector LED thingy/bug
Post by: Gyro on December 04, 2017, 09:35:56 pm
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!
Title: Re: GSM em-radiation detector LED thingy/bug
Post by: MasterT on December 04, 2017, 09:48:52 pm
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.
Title: Re: GSM em-radiation detector LED thingy/bug
Post by: calli on December 07, 2017, 03:55:22 pm
I have a G2 mobile here. No lights.

Carsten
Title: Re: GSM em-radiation detector LED thingy/bug
Post by: jmelson on December 07, 2017, 10:40:13 pm
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
Title: Re: GSM em-radiation detector LED thingy/bug
Post by: calli on December 08, 2017, 08:18:15 am
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
Title: Re: GSM em-radiation detector LED thingy/bug
Post by: Kalvin on December 08, 2017, 01:51:30 pm
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.