Version 7
    Pripyat - DIY Geiger Counter

    element14 Presents  |  AirborneSurfer's VCP Profile |  Project Videos

     

    Matthew goes atomic punk in this video where he takes some old Soviet surplus Geiger-Muller tubes and builds his own recreation of a Civil Defense-style Geiger counter. The CDV-700 series survey meters were developed in coordination with the US government at the height of the Cold War for deployment to local Civil Defense authorities. With a few off-the-shelf parts, Matthew builds a high-voltage circuit to power the GM tube and uses an Arduino Nano to process the output signal, driving the characteristic click and dancing analog meter, then encloses it in a custom 3D-printed case completing the homage to this mid-20th century piece of vintage tech!

     

     

    Product NameQuantity
    Buy KitBuy Kit

    Perfboard

    1Buy NowBuy Now

    110V to 6V center-tap transformer

    1Buy NowBuy Now

    555 timer and socket

    1Buy NowBuy Now

    0.1uF 50V electrolytic capacitor

    1Buy NowBuy Now

    0.01uF 700VAC film capacitor

    2Buy NowBuy Now

    1N4007 diode

    2Buy NowBuy Now
    0.01 uF 1kV ceramic disc capacitor3Buy NowBuy Now
    4.7k resistor4Buy NowBuy Now
    12k resistor1Buy NowBuy Now
    100k resistor2Buy NowBuy Now
    BUZ71 MOSFET1Buy NowBuy Now
    2-pin screw-on connector set1Buy NowBuy Now
    SbM-20U Geiger-Muller tube (any tube will do, but you'll have to adjust for different input/output voltages)1
    1M resistor2Buy NowBuy Now
    330 resistor1Buy NowBuy Now
    2N22222N2222BJT 1Buy NowBuy Now
    Arduino Nano1Buy NowBuy Now
    Piezo buzzer1Buy NowBuy Now

    5V moving magnet analog panel mount meter

    1Buy NowBuy Now
    SPST panel mount toggle switch1Buy NowBuy Now

    LED

    1Buy NowBuy Now

    Adafruit PowerBoost 1000

    1Buy NowBuy Now

    LiPo battery

    1Buy NowBuy Now

    Wire

    1Buy NowBuy Now
    Solder1Buy NowBuy Now
    3D Printer Filament1Buy NowBuy Now

     

    Matt Eargle is a cold war nut who loves historical technologies. He just happens to have some old Soviet surplus Geiger tube sitting around.   He’ll use it to build his own take on a Geiger counter.  It will be something like an updated CDV 700 series. The original CDV-700 Series models were in production from 1954 until 1974.  Later XXX series models were produced well into the 1980s. In order to build a homebrew version of a Geiger counter, he’ll need a couple of components in addition to his Geiger tube.  A Geiger tube has a sealed vial inside a sealed glass tube containing an inert gas. You take that and apply a really high potential, the one he’s using is about 400 volts. When your particle comes in and strikes the nucleus of the gas inside, it temporarily ionizes that gas, just enough to allow some of that voltage through that it can be measured.

     

    He’ll need a high voltage source to feed his tube.  The cathode of the tube will run into an Arduino.  Running the high voltage source through batteries will require a transformer.  The transformer will require an AC current.  The easiest way to create an AC current would be to create a little oscillator with 555 timers and run that into an inductor.  The 555 timer will set up in astable mode to produce an alternating signal at 60 Hz that will get amplified by a MOSFET before running into the transformer. The current from the transformer will go into a diode laddering system which will drive the GM tube.  The signal from the Geiger tube will run into an NPN transistor.  The output pulse of the tube is around 200V, so it needs to have some level of conditioning before it can be counted by the Arduino. Once the output is run into ground they’ll have a digital signal that they can feed back into the Arduino.

     

    He tests the circuit in a breadboard to make sure it works.  The output of the Geiger tube is hooked into an oscilloscope.  Matt uses an old aircraft instrument, an ADF with a glow in-the-dark radium dial to test to ensure that a signal is outputted to the scope.  Now that we know the signal is working, we can condition that signal to create a digital pulse that we can measure and count with the Arduino.  The tube output runs through a voltage divider so that it doesn’t fry the transistor.  All that’s left is to 3D print some parts and do some coding using the Arduino IDE.