A VALVE TESTER ACQUIRED

AT A RADIO RALLY

I acquired this old Radio Valve tester at a radio rally just before lockdown. It needed a bit of restoration work, general cleaning up, replacement of mains lead, and switch cleaning. Unfortunately it would not measure the more recent valves, and I had to make an adapter to take B9A type valves.

The B9A adapter in course of construction, and plugged in to an octal valve socket.

A HOMEBREW RADIO VALVE TESTER

As I was unable to measure the more recent types of Radio Valves, I decided to embark on the construction of my own Valve tester, as a sort of lockdown project!

It basically used this circuit, but heavily modified. The aim was to be able to measure grid voltage, anode and screen voltage, and anode and screen current simultaneously

Here are the layout plans I produced in Illustrator

for the power supply and valve holder section.

The power supply layout was modified

over the course of the construction.