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!!

I once built a power supply that oscillated above 150 MHz.
Unfortunately, I could never drop it into the 2-meter band.

--Myron.
--
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTX). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)