Roam The Wastelands With This Fallout-Themed Mini Geiger Counter

For anyone who has worked with radioactive materials, there’s something that’s oddly comforting about the random clicks of a Geiger counter. And those comforting clicks are exactly why we like this simple pocket Geiger counter.

Another good reason to like [Tim]’s build is the Fallout theme of the case. While not an item from the game, the aesthetic he went for with the 3D-printed case certainly matches the Fallout universe. The counter itself is based on the popular Russian SBT-11A G-M tubes that are floating around eBay these days. You might recall them from coverage of this minimalist Geiger counter, and if you were inspired to buy a few of the tubes, here’s your chance for a more polished build. The case is stuffed with a LiPo pack, HV supply, and a small audio amp to drive the speaker. The video below shows it clicking merrily from a calibration source.

We can see how this project could be easily expanded — a small display that can show the counts per minute would be a great addition. But there’s something about how pocketable this is, and just the clicking alone is enough for us.

46 thoughts on “Roam The Wastelands With This Fallout-Themed Mini Geiger Counter

    1. Hello Jensma,
      a standard plastic box… seriously, what’s the point. Why not go for a standard geiger counter completely then that would really look nice. Ohhh… whoops it would not be a project then.
      I don’t think that the 3D print looks that terrible at all, sure there is room for improvement, but it does the job.

    2. I agree that the quality of the 3D print is sub standard, but hey, you got to use that $300 3D printer for something.

      I have the exact same experience, I printed a case for a Raspberry, but ended up replacing it for a $1 case from flebay.

      Consumer 3D printing has a looooooong way to go still, if you are going to use the prints for something other then dustcollecting.

      I have seen more expensive consumer 3D printers with better print quality, but the price of those are way higher.
      I guess you get what you pay for.

      1. Yeah I thought it looked decent for a 3D print. I do agree with the post about using some filler and sanding it before painting. A bit more effort in finishing the print would go a long way.

  1. I’m lazy and would have used “losalt” as my radiation source. At 66% potassium chloride, and 0.012% of all potassium being potassium-40, it should be a good enough for test purposes. with beta particles (@ 1.33 MeV, 89.28% of the time when it decays into calcium-40) and gamma rays (@ 1.460 MeV, 10.72% of the time when it decays into argon-40). And since at low household quantity this is only about 3x the natural background radiation it is enough to be detected and very safe to be around if you mess up and sneeze or something.

      1. The problem with a BED is that it has so little potassium spread over such a large area, with a basic Geiger counter, it takes a minute or more of measurement to detect the difference in background levels. It is just not a big enough jump in levels for a quick demo.

    1. Correct me if I’m wrong but 1.322MeV is the energy released in electron annihilation as gamma radiation. Potassium z is 19 and calcium 20 so it should be a beta – (elecron not positorn) which won’t annihilate right( without a source of antimatter)

    2. It’s not too difficult to find a cheap radioactive sample on eBay. Look for uranium minerals like autunite, torbernite, uranocircite or plain old pitchblende :) If nothing else, there’s still old Fiesta ware and depression glass.

  2. ncieI’m lazy and would have used “losalt” as my radiation source. At 66% potassium chloride, and 0.012% of all potassium being potassium-40, it should be a good enough for test purposes. with beta particles (@ 1.33 MeV, 89.28% of the time when it decays into calcium-40) and gamma rays (@ 1.460 MeV, 10.72% of the time when it decays into argon-40). And since at low household quantity this is only about 3x the natural background radiation it is enough to be detected and very safe to be around if you mess up and sneeze or something.

    1. Correct me if I’m wrong but 1.322MeV is the energy released in electron annihilation as gamma radiation. Potassium z is 19 and calcium 20 so it should be a beta – (elecron not positorn) which won’t annihilate right( without a source of antimatter)

      1. Ha. I recall reading an anecdote years and years and years ago about a class of university students that were studying, I don’t know exactly, radiation in an urban environment or something and set up radiation monitoring equipment in the lobby of a downtown office building with an all granite facade.

        Allegedly when they saw the initial radiation readings, they immediately left the building abandoning their equipment.

  3. IIRC those eBay Russian tubes aren’t very sensitive (I think the citation is a HAD post). So this is actually a nicely finished project, (and remember, the difference between Project and Product is just 2 letters) but could it be under-reporting?

    1. I don’t think there’s anything wrong with the Russian tubes in particular. Of course, if you pick a tube that’s very small it’s not going to be very sensitive. I’ve used a different Russian tube, STS-5 (SBM-20) which is longer than the one in this post. I get about 20-25 CPM from background radiation.

      1. I have the SparkFun Geiger counter – but I don’t know how accurate it is either. There’s probably a comparison on the Goog somewhere, but I’d hate to have a device that is under-reporting :-) Some very insightful person on HAD was talking about why medical devices are so expensive – it’s because you have to get past the vagueries of the sensor to match reality.

  4. Wouldn’t a scintilation counter be easier?
    Perhaps only useful on higher radiation rates but I remember seeing a schematic for a cheap keychain radiation detector for cops and firefighters which lasted about 10 years on a lithium cell using a tiny microprocessor to run the rate counting logic, the scintillation flash sensor, and the piezo beeper..

      1. Digital X-Ray detectors are state of the art now. A grown crystal substrate is attached to a massive x/y array of phototransistors with amplification and a sample and hold for each pixel, then this array of readings is scanned into the computer and displayed. dave mentioned scintillation and what we were taught was scintillation is a single event… but the way they are taking x-ray images now is illuminating the array just like it was used to “illuminate” and expose the film with a massive number of events over a short period of time over the entire field all at once. It’s still scintillation that is being used, but in the old days scintillation generally spoke of a single gamma event, but now it means “We make the screen glow and tell the transistor array to integrate/sample/hold, then we scan the array for readings.” Those arrays are ungoshly expensive… and the salt crystal in front is still slow-grown just like it was for nuclear medicine.

        Yes, they are being made now. Made to show rate of dose rather than bothering with single scintillation events. Measures overall glow of mass number of scintillation events.

        Alas… just not sensitive enough for use in a grocery store.

  5. Everyone’s complaining about how great/bad it looks and here I am wondering about what people in radioactive zones do if they accidentally walked into a radioactively-dangerous area. What do they do after that? Do they have a recovery plan or do they like, just accept it and move on?

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