Being an engineer I was more or less convinced that all the fuss about Atomic Energy was exaggerated. Yes, the problem with nuclear waste was serious but I thought it could be solved.
The Three Miles Island accident did not change my believes: after all the famous China sindrome did not happen and there was no melting (that was the information spread those days, now I now that there was a meltdown and a serious release of radioactivity).
Then Chernobil came: no fresh vegetables for more than three months. Terrible accident, but one could blame it to poor soviet technology and procedures.
But when I saw unit 3 blow up in Fukushima Daichi I was finally horrified. And when I learned that authorities in US and EU stopped releasing environmental data until they had substantially raised the maximum acceptable level I came to the conclusion that it was better to be prepared and have one own measurement system.
At that moment I only had an old V-700 radiological survey meter. It is in mint conditions and working properly, but unsuitable for environmental monitoring.
So I first set up a monitoring station with a geiger tube (see NSBRM). When I discovered that I could also build a gamma spectrometer I started purchasing the parts to assemble my own. And, in order to calibrate it, I started looking for radioactive source online. Finally I managed to get a spark gap (137Cs), four lantern mantles (Th), and a piece of uranium ore (quite radioactive!). I also purchased a Sylvania OC3 and three Raytheon OB2WA looking for 60CO, but given the short half life I got no useful signal from them.