Hi from New Jersey

Location: Columbus, NJ, USA (approx 15 km south of Trenton)
GM Counter: RH Electronics DIY Kit Version 3.00
Tube: STS-5

More than 50 years ago, using a schematic I found in a library book, I constructed a GM counter from scratch to earn the Boy Scout Electronics merit badge. The merit badge counselor helped me troubleshoot it and it worked after we found I had reversed the transformer primary and secondary connections. Several times I recorded large background count increases when fallout from atmospheric nuclear tests passed over my home in the USA Midwest. A few years later my homemade GM counter got scrapped while I was away at college and I've always regretted its loss.

This week I ordered a GM counter kit from RH Electronics and an STS-5 GM tube from an eBay seller in the Ukraine. I will hopefully receive the parts and get it online by mid-January. I plan to interface the GM counter to a Raspberry Pi computer I currently use to receive and upload aircraft ADS-B transmissions.

John DeGood NU3E

Welcome John, It's good to have you back in the fold!
I like your story