Geiger Counters, Radiation, Electronics, Projects and Other Good Stuff

I wanted to see if there was much difference between the sensitivity between a SBM-20 and STS-5 tubes. For a background test I had an SBM-20 running for a while then swapped it for a STS-5. I think the graph says it all. (Note - there was a discrepancy with the initial background test (below). The test was repeated later and the results are shown towards the end.) I took this a step further and compared the two tubes using 13 different sources. In hindsight I should have tested a J305 at the same time. It took a surprisingly long time, so I might set up some kind of testing jig and program an

It seems of late that getting hold of good GM tubes, for reasonable money is a thing of the past. A single SBM-20 on eBay is going for in excess of £150 ($182) and there are hardly any suppliers left for them. Some years back I paid about £13 for a NOS SBM-20. I wish I had the nous back then to buy a large stock of them. I'd have made good money these days! eBay used to be awash with good GM tubes. Lots of regular types, SBM-20, STS-5, LND-712, SBT10A, SBT11A, pancakes, a bunch of Mullard and then a load of quite exotic tubes. Today there is hardly any of those and is covered with cheap

If you are interested in Chernobyl you will love this video. I had only heard of SKALA in the past, but nothing actually about it. This video gives a really good look into SKALA and it's operations. In this episode of Computers of Chornobyl series, we will talk about the mighty SKALA system, that controlled the RBMK reactors. This is the first-ever documentary about its design, architecture, operation, and software. It also tells the story of how it was preserved for posterity and reveals, what is common between it... and a control computer of Apollo spacecrafts. It took us nearly half a year

I bought one of these cases from my local Asda for about £14 a few years back. I thought it was that good I went back a week later and they had sold out and they never came back into stock again. I had a little search about on the internet and found them on eBay and Amazon - links below. I bought one from eBay to see if it was the same quality, and it is exactly the same. It is a really neat case. Appears to be very waterproof, even air tight and strong. I think it is made from Polycarbonate. I used mine to house a GPS Geiger counter project some time ago. I think I will use another for an

For all of the posts in the Negative Ion Energy Ju-Ju series, click here. I found a new variation of the pendant. A white Ju-Ju pendant. I think there are loads of variations but this seems a new one. I have one on the way so will let you know about it when it arrives. https://www.aliexpress.com/item/4000030351480.html Update: It has landed! This is the latest Negative Ion Energy Ju-Ju pendant. It's kind of pretty. File Attachment: It has some extra goodness on the back - some Germanium stone and FIR stone little dot kind of things. One of the previous stone coloured pendants has 4 little dot

I was asked by Gissio to try and download the original firmware from my HFS-P3, so I tried. Alas, no joy so far. ☹️ Under the battery (stuck down with sticky tape) is a pin header. Probably designed to have a pogo pin connector connect to it as there is no room to solder on an actual pin header. I just soldered wires to it directly. I managed to work out the pins by tracing the circuit, but I had to use my microscope as the connections on the MCU really are that small! I took photos of both sides and flipped one then overlaied one over the other so I could line up the vias on the board. You

Early afternoon and I hear a mighty humming noise. A swarm of bees had come to visit! 😊 After I had run around the house closing the windows I caught a bit on video. I've never been this close to a swarm of bees. Being behind a window was great as they were super close. I did consider going outside but they moved off shortly after filming them. They also came back a few hours later but didn't hang around and I didn't get my camera in time. I think they may have been mating as there seemed to be two swarms which you can't really see on the video, but that is the reason I moved the camera from

I have been trying to find info on this tube since I got my HFS-P3 Chinesium pen counter, with little to no avail. By chance, a new user to radmon.org (gissio - welcome!) has already found the info and manufacturers website so I have compiled an English version datasheet for this tube (below). Many thanks to gissio for the info! ( https://github.com/Gissio/fs2011pro/tree/main/docs/tubes ) The HH614 is a new tube to the market, released in June 2022. It's quite compact but the size does limit it's sensitivity somewhat. It's gamma sensitivity is 10 CPS/mR/hr compared to the SBM20 at 22

For all of the posts in the Negative Ion Energy Ju-Ju series, click here. 'Ponit' !!! LMAO 🤣 I think that should be 'Point'... Yes, another potentially dangerous Ju-Ju device. Thanks to FSM19 for pointing me to this. It is rather interesting. It comes in a little black cardboard case but sadly no authenticity card. It does have a little leaflet inside (below) with the usual bullshit and spelling/grammar errors to boot. The text isn't even complete and ends with 'and improves nutrient take up by the' and that is it! Muppetry at it's finest. 😂 Its a very interesting piece. Much like all of

For all of the posts in the Negative Ion Energy Ju-Ju series, click here. Round three, four, five? Of Quantum Energy Thorium Radiation Ju-Ju FIR Energy Stuff That Will Not Do You Any Good! Yay! 😄 The more you look for these things, the more you find. It's insane! And I bought some. A pretty glass pendant and a lovely set of a pendant and plastic card. And the glass pendant and plastic card are considerably hotter than the previous pendants. All bought from Ali Express and all containing Thorium. Here are my findings. I messed up with the camera again, a bit, and there wasn't enough light so I

Here are a couple of interesting videos taken inside the damaged Chernobyl reactor 4. The following comment was posted on the first video that lends a little information about who and when the video was recorded. The second video (in Russian) I picked up from the comments of the first as someone was asking what kind of protective clothing did they wear. It's not quite as interesting as the first video, but still interesting nonetheless. Comment from the first video by user J4yChu: I’ve researched, and come up with a few things about the video! The person filming is Alexander Kupny. He was a

For all of the posts in the Negative Ion Energy Ju-Ju series, click here. A while ago I saw a video (below) where the creator had purchased several 'Negative Ion Energy' products that actually contain radioactive Thorium. Most of these products are wearable items and some other 'Nume' cards, or whatever they are. At the time I searched for these but seems they had all been pulled form the stockists shelves. Then I saw a more recent video by the same creator and searched again, and lo and behold, the same products are stocked up again and readily for sale - to unsuspecting people that may

A cheap and easy way to change a blue LCD or OLED display to yellow/amber using Kapton tape. I don't like blue displays. I never have done. I have always found them to be harsh on the eyes, especially in dark environments. I also find them more difficult to read than green or yellow displays. Blue is a colour that is rarely found in nature. It really was a colour that was/is quite unnatural to the eyes until recent times. It reduces melatonin release into the body and can affect sleep. I discovered some years back that Kapton tape can change blue displays into yellow/amber just by simply

My J305βγ tube is very light sensitive so I made a quick video demonstrating this. I shine daylight (on a miserable cloudy grey day) on the tube at first, then a 365nm UV flashlight and finish off with daylight again. The effects seem to work only at the anode end and not at the cathode end. Doing a little research I found that the light sensitivity of GM tubes only occurs in glass walled tubes that have an external cathode. The specifications show this about the tube wall: Tin oxide Cathode, Coaxial cylindrical thin shell structure (Wall density 50+-10cg/cm2). The cathode is on the exterior

A member (of radmon.org) asked me if the Gamma Scout would/could work with radmon.org using the USB and software the counter came with. The answer to that is a simple, no, not out of the box, but it could be done with a quick hack. Simply add a couple of wires and connect them straight to an ESP8266 or similar MCU. This guide only covers the 'Alert' model. There may be differences with other Gamma Scout models. Here is how: Open up the Gamma Scout and locate the small transistor at the top left of the board, right above the pin header. There we are going to solder on a wire to the middle pin

Here are some pictures and details about the SI-8b (СИ8Б) Pancake Geiger Muller tube. The adhesive failed between the tube and the Bakelite rear case on my tube, so it would be rude not to take it apart for a look! From what I understand this tube is designed for soft beta detection, but is also capable of alpha, hard beta and gamma, although calibration would center on soft beta particles. I did however read this from a website: 'This Geiger-Mueller tube is only sensitive to β and γ radiation. The calibration is only correct for the γ radiation (662keV) emitted from Cs-137.' I will test at

** Note: This is for submission of CPM readings to radmon.org. This was working at the time of writing but updates to libraries may cause issues. Here is some Arduino code for the Arduino Uno, Mega2560 and Pro Mini with WizNet W5100 ethernet shield. This is bare-bones code only. It does only these things: receives pulses on pin 2 (Uno, Mega & Pro Mini), calculates CPM and submits it to Radmon.org (via ethernet shield) every 60 seconds. It has a little debugging that can print to serial and I have also added CPM print to serial (much like the NetIO GC-10) that can be used with the Radlog

I have seen these kicking around the usual suspects (Ebay, Amazon, Aliexpress etc.) for a little while now and after watching (a not very informative YouTube video) I decided to get one and see just what it is and is it any good. TLDR; You get what you pay for. I paid about £32 for this from Aliexpress.com but have seen them for as little as £25 on Aliexpress.com and as high as £60 on Ebay and Amazon. The unit is very small and packs a tiny 150mAh LiPo cell, 48mm x 7mm (external dimensions) HH614 GM Tube, tiny OLED screen, a massive overkill ARM Cortex-M0 FM33LC043N MCU from Fudan Micro and

I recently obtained some radioactive rocks from an eBay seller for a low low price of..... £1 each! 😆 Plus £8 shipping each... 🫤 I didn't realise how much there really was until I weighed them, and they come in at a whopping 14.5 lbs, or 6.6 kg! 😯 I believe they have come from the South Terras Uranium Mine in Cornwall. The mine was closed back in 1930 and apparently the mine itself is inaccessible since then although someone gained access and took some pictures of the mine itself. It is still very radioactive now. Some of the buildings above ground still exist and I think that is where my

** Note: This is for submission of CPM readings to radmon.org. Here is some Arduino code for the ESP8266 written and tested on a Wemos D1 Mini. This is bare-bones code only. It does only these things: receives pulses on GPIO 13 (physical pin D7 on Wemos D1 Mini), calculates CPM and submits it to Radmon.org (via WiFi) every 60 seconds. It has a little debugging that can print to serial, flashes the internal LED when an interrupt event is detected and I have also added CPM print to serial (much like the NetIO GC-10) that can be used with the Radlog windows logging software - and that is it.