SET UP.
A
B
C
MATERIALS
Get the Maker Shed kit (MKIS1) for a
GMT-01 tube, PCB, and all electronics
(except voltmeter, data logger, and
batteries) at
makershed.com, $170.
A. Geiger-Müller (GM) tube
I recommend GM T-01 ($100), GMT-02
($75), or GM T-06 ($50) from Images
SI (
imagesco.com). The GM T-01 is a
U.S.-made LND 712 tube that detects
all 3 radiation types.
D
E
B. Geiger Counter PCB Images SI item
#PCB- 52. You can also wire this circuit
together on a plain breadboard.
E. Radioactive source (optional)
for testing. You can use uranium ore
but a more reliable source is cesium- 137,
which comes in 5μCi (microcurie) and
10μCi plastic sample disks. See make
projects.com/v/29 for sources.
or other values dependent on GM
tube used; see Step 1c.
» Potentiometer, 1MΩ
» Switches: SPDT toggle ( 1),
SPDT slide ( 1)
» Transformer, mini step-up
Images SI #HV T-03
» Rectifier, 1.5A bridge, W01M, 100V
» Comparator chip, quad, LM339,
DIP14 package
» Piezo speaker
» Socket, 14-pin DIP
» Terminal block, 3-contact screw
or 4-contact
» Wire, insulated, 22 gauge stranded,
red and black
» Battery, 9V
» Battery snap for 9V battery
» Fine metal screen (optional)
to protect GM tube mica window
C. Data logger (optional) Lascar
Electronics EL-USB- 5, item #2127048
from Jameco (
jameco.com), $82
D. Voltmeter (optional, for analog
meter), panel-mount display,
1V DC full scale Lascar Electronics
EMA-1710, Jameco #2095082, $34
» Capacitors: 0.01μF, 1kV ( 4); 0.1μF
( 1); 10μF, 16V ( 2); 1,000μF, 16V ( 1)
» Diodes: 1N4007 ( 5); Schottky
1N5817 ( 1); Zener 100V 1N5271B
and 200V 1N5318 ( 3 total, see
Step 1a); Zener 5.1V ( 1)
» LED
Gregory Hayes
» Power jack, 3.5mm DC, PJ108
» Transistors, NPN: 2N3904 ( 1),
» Resistors, ¼W: 75Ω ( 1), 100Ω ( 1),
10kΩ ( 5), 100kΩ ( 1) , 1MΩ ( 2),
1.8MΩ ( 1)
» Resistors, ¼W: 470kΩ, 10MΩ
100kΩ ( 1), 500kΩ ( 1)
» Diode, 1N914
» Capacitor, 1μF
» Resistors: 100Ω ( 1), 390kΩ ( 1)
» Switches: SPDT toggles ( 2),
SPST toggles ( 2)
» Perf board, small I used half of
a solderless-breadboard-matching
board, RadioShack item #276-170,
radioshack.com.
» Ruler
» Small project box, plastic or other
non-metal enclosure, Mine measures
5. 6"× 3. 2"× 1. 5". You can download a
template for the laser-cut case on
page 101 at
makeprojects.com/v/29.
» Machine screws, small, with matching nuts and washers
» High-speed rotary tool e.g., Dremel,
for cutting holes in plastic box
For the data logger:
» Battery, 9V
» Computer, Windows-based
» Software for graphing data sets
such as Microsoft Excel
For the Digital Meter Adapter:
» Digital Meter Adapter (DMAD),
Images SI #DMAD- 3, $60 as kit
or $90 assembled
For the analog meter, calibration,
and enclosure:
» Potentiometers: 47kΩ ( 1),
TOOLS
» Soldering equipment
» Multimeter
» Radiation Network software
and cable (optional) from
radiationnetwork.com, $79
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