I own a CDV-700 geiger counter of which the tube stopped working. It turns out that replacement tubes are both hard to find and expensive. The simplest option is to buy the LND 720 which basically is a drop-in replacement that should cost about $100.
It’s also possible to use cheaper, easier to find tubes with the CDV-700. I found the following post from radio amateur K0FF on the “Geiger Counter Enthousiasts” group on Yahoo groups. It describes a simple circuit to adapt tubes of varying voltage to the CDV-700. I built one, and it works! Continue reading Post ID 859