Mr Blinky

Here is a 24 day and 10 hour long accumulation from a glow in the dark Tritium tube, vial, thing. It's just like the ones used in fishing indicators, clocks, watches and military defile markers. Often called 'beta lights'. Total counts: 76,669,829 😄 The massive peak at ~11.8 keV is from Zn Kα X-rays emitted as the Tritium hits the zinc sulphide phosphor and the smaller (~85 keV) peak is most likely from X-ray fluorescence from materials near the detector, or could be backscatter from the detector housing. My spectrum is ever so slightly out by 2-3 keV as the peak is shown on the chart at

Vintage (circa 1944) Victoreen 6107 / BS 212 GM tubes & HV PSU I picked up these little gems (and they are!) along with a (matching?) power supply, crystal earpiece and instructions on using them to make a rudimentary Geiger counter. I got them for £26.20 shipped, which I think is great price for these pieces of history, although they were sold as parts and unknown if working/no way to test. As it happens, both tubes work great! One tube came wrapped up in vintage fluff in it's original box and the other tube was loose. The loose tube was in worse condition than the boxed one. The boxed

I couldn't wait to tinker with this so I decided to mod this in lieu of getting the ESP-12 modules and programmer. Using a scope I found the connection points I needed, Soldered some wires on. Soldered a Wemos D1 Mini clone on the other end, installed ESPGeiger 0.7.0, and boom! Literally as simple as that. Using the scope I checked the ribbon cable pins one by one and found the pulse coming from the PSU board. I didn't want to solder right on the ribbon, it looks janky already, so probed about and found that it is connected to L12. The MCU side of the inductor is where I soldered the pulse

Yaorea YRG01 I bought another cheap Chinese counter from Aliexpress and I am impressed, especially for the price of £27 shipped to my door. Despite its cheap appearance it actually offers a lot of bang for buck. I haven't looked into it closely, but there seems to be a lot of attention to detail, and I reckon whoever designed this really gave a damn about it. 😄 It came up in suggested products on Aliexpress and I wouldn't have bothered about it if not for the fact that someone reviewed it and posted pictures of its insides. "Okay, a glass tube... Ooh a separate PSU board with a big hunking

This is a comparison of 8 glass walled GM tubes, with a SBM-20 as a control. I did this some months ago, but hadn't pulled all the data together until now. Of the eight tubes, four are of the J305 flavour - M4011, J305 (2021 - light sensitive), J305 (2023 - not light sensitive) and one that appears to be a copy, with no markings and came in a cheap FS-2011 Geiger counter. The other four are more interesting, or less, depending which way you look at it. The HH614 is from a pen type counter and is quite small and thin. The remaining three are very low sensitivity tubes designed to be used in

I got these tubes just to see what they were like. I was a little surprised to learn that they are black due to a sleeve of heat shrink over the tube. I had previously thought they were black due to them being an opaque glass, but after peeling a little of the sleeve off it revealed tin oxide coated clear glass, much like the J305. I accidentally rubbed the markings from the J306 when cleaning it, as I have done on a J305. The markings come off very easy with these tubes. Going from top to bottom - J306, J307 then J308. Specs from Alibaba: Below is the background comparison result. Each tube

I want to build a radiation shielded chamber for Gamma spectroscopy using my Radiacode 103. After batting some ideas about on another thread this is what I have so far: Outer case is 6mm steel (mild steel) - This could be a square tube section, or made from sheet. Inner case is the same as the outer and has 60mm x 60mm to 75mm x 75mm (thereabouts) space in the center for the Radiacode and source. Internal length of the chamber will be ~200mm. Space between the inner case and outer case will be filled with lead, ~25mm thick. Tabs/flange on both caps and outer case to put bolts through to fix

Here is a 12 hour spectrum accumulated on the Radiacode 103 of a spicy Sr-90 (Strontium-90) check source (~100-200 Bq) from a DP-5 Geiger counter. Both Lin and Log are shown. Archived from radmon.org - originally posted 06/04/2025

Experiment - Capturing Radon progeny from Uraninite (Uranium ore) This should be quite interesting to anyone that owns or is thinking of owning Uraninite (Uranium ore) sources, and anyone with a keen interest in Radon. TL;DR - Skip to the last part for safety concerns with U-238 sources and also Thorium gas mantles, Thorium dioxide. This was a fairly well controlled experiment that was carried out at home, and using ChatGPT as my lab sidekick. The idea was to capture Radon progeny from 4.46g of Uraninite (Uranium ore) and prove the decay products. Uraninite emits Radon gas and this decays

I have just picked up a couple of Mullard MX-124 GM tubes on ebay for a song! I originally bid a fair amount that I immediately regretted, but when the auction finished I got them for a really good price! There were two tubes in the auction and one came with original datasheet and Mullard guarantee . They are quite unusual in they are designed to detect radiation in liquids. Their construction is like a glass walled GM tube inside a test tube, with a stopper on the end. They are to be used in a vertical position and the liquid poured into the top of the tube and the liquid will run down to