John
Don't know about St. Helens. My stint was from Jan 1960 to Jun. 1962, when I went in the RAF.
I think all Instructors of the time were specially selected, harsh but fair ... same can be said of Area Bombing I suppose

Yup, we used Mercury Arc Rectifiers etc. And their big brothers, Ignitrons. Used to frighten the life out of me. Hideous things ..
The first transistors I used were the GEX series IIRC. Dead as soon as you picked them up. Valves we used on instrumentation were often ECC81.
Ah Nixie tubes, decatrons, ... all the old stuff.. still some sites on the WWW using them, God knows why ?
We are ancient, some of us more than others ...

but still ticking... slowly ...
Gone a bit

I think.
Dave BC