2022

Archived from radmon.org - originally posted 23/12/2022 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

Archived from radmon.org - originally posted 12/12/2022 ** 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

Archived from radmon.org - originally posted 11/12/2022 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

Archived from radmon.org - originally posted 13/11/2022 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

Archived from radmon.org - originally posted 20/02/2022 ** 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

Archived from radmon.org - originally posted 16/02/2022 I was repairing an old Russian DP-5V counter yesterday and noticed an unusual neon/orange flashing glow coming from the probe PCB that I have never seen before, so decided to investigate. It is caused by two thyratrons on the board, flashing away with the clicks of the counter. They are similar to modern thyristors in their function. These thyratrons are filled with neon gas, hence their orange glow. This is from wikipedia: https://en.wikipedia.org/wiki/Thyratron Conductivity of a thyratron remains low as long as the control grid is

Archived from radmon.org - originally posted 13/02/2022 Following on from Pt.1 - Here are some pictures of the battery compartment. You can see the terminals at the bottom pivot in the middle like a seesaw, also with one battery inserted and then with two. I couldn't resist and took out the tube to have a look at it. It is rather large, pictured below next to a STS-5 tube (SBM-20 equivalent.) ↑ Seesaw battery terminals with pivot at the center. ↑ ↑ One battery inserted. ↑ ↑ Two batteries inserted. The cap has a large shaft that pushes down on the positive terminal, the battery is pressed down

Archived from radmon.org - originally posted 13/02/2022 This is one of my latest Geiger counters and it is in fantastic condition. To say this is probably more than 60 years old, it has really faired well. It wasn't working when I got it as one of the battery terminals had some corrosion to it. After a quick but very awkward clean up of the terminal it came to life. What really attracted me to this, besides it's condition, is the fact the meter is in CPS (counts per second.) I thought it unusual for a small counter of this era to be in CPS. Being CPS would mean it would be sensitive, which it

Archived from radmon.org - originally posted 06/02/2022 I have translated the manual with the help of a couple of internet AI translators. Attached below you will find a couple of PDFs of the original Russian manual and an English translation of the manual, also the text of the manual in .txt format. The PDFs quality isn't great as the images weren't great but they work. The text version is probably easier to read. A couple of things about operation that I was puzzled about were the mains/missing psu and missing battery. From reading the manual I'm assuming that this was in fact a "Lux"

Archived from radmon.org - originally posted 05/02/2022 I have managed to power this up and it does work! 😊 I have also started reverse engineering it a little. I removed the two (brass?) strips and replaced them with wires so I can flatten the board out properly. The two strips were connecting the ground and VCC on the boards together. I haven't yet translated the manual, but I will in due time as I can't find a single thing about this counter on the internet at all and the info may be of use to others' too. In all it seems like a very basic counter with a quirky display. If I knew what the