February 2022

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

Archived from radmon.org - originally posted 01/02/2022 I found this on ebay priced at £12.52 delivered and couldn't resist at that price so I bought one for shits and giggles! Probably the most bizarre counter I have bought yet. (Apologies for the camera focus - new camera, very complicated... 😯 ) I haven't powered it on yet as I have no idea what battery it should be, if it should be a battery at all. It has US mains plug pins on one end but there is nothing wired to it, nor is there a battery cover. The only way to put a battery in is to disassemble the unit, which is rather cumbersome. It