April 27, 2019

Introduction

I ordered one of these 4/5/2019 on Banggood for $34. It arrived 4/25/2019, which is typical for items ordered from China. It was in a lightweight bag, wrapped in a thin foam sheet. The tube had come loose, but was unbroken. However, I see fragments of glass rattling around loose inside the tube. We will see if this works or not. It arrived with a battery holder (for 3 AA cells) as well as a cable to provide power via a barrel connector from USB. Also provided is a stereo 1/8 inch (3.5 mm ?) patch cord as well as a mysterious 3 wire jumper. There is also a switch (who knows what it does -- it turns out it is a power switch!) There are a couple of jumpers (both installed). There seems to be virtually no documentation as such. I used their google drive info link and downloaded all of the files they offer.

Try it out

I got brave and connected it to a USB charger I had laying around. This works just fine, and apparently my unit is functional. I set the unit on top of a box of uranium minerals I happen to have, and it gets quite excited.

D24 is apparently simply a power LED. D23 flashes at the same time there is a click, so you get both a visual and audible indication of radiation.

Use with Arduino

I have no intention of doing this, but apparently that is what the 3 wire jumper is all about. You will need to solder on your own 3 pin header to P3. This will bring 5 volts and ground from the Arduino, and will send a signal via the "Vin" pin.

J305 Geiger tube

The listing claims that the unit can work with a variety of geiger tubes. Mine came with a J305, but the listing mentions M4011, STS-5, SBM20, and J305. Here are some specs on the J305 from an Ebay listing: They say it will detect both Gamma and Beta radiation.

Links

Have any comments? Questions? Drop me a line!

Tom's Electronics pages / tom@mmto.org