Jock Cooper wrote:

I tried numerous circuits and numerous types (Hartley, Colpitts etc) I
had found but I couldn't get any of them to start up.

Oh, that's easy. You're *trying* to build an oscillator; give up on
that goal and choose an easier one: try to build an amplifier. I mean,
really *want* to build a stable amplifier. Voila! An oscillator!!

Dana K6JQ