My "simple" valve tester

[ppppenguin]

For something like this either build it on tagboard or matrix board (aka pin board). I use the latter for much prototype and experimental work. It's like Veroboard without the copper strips. You use pins that are a push fit in the holes. Wiring is with tinned copper wire, with sleeving as needed. Sometimes insulated wire for longer and irregular runs. More flexible than Veroboard and no risk of insulation breakdown between adjacent tracks.

Here's a photo of a PAL coder that I designed and built in 1987 using matrix board. I've still got it and it still works. It was originally designed to give near broadcast grade PAL output from a BBC Micro. My client put it into production, we designed a PCB and it sold quite well.