Again, due to the breadboard affects on crystals, my circuit was slightly different than Alan’s by the lucky trial and error of my incorrect cap value components removal – including a floating caramic cap at the base of TR1 – at full PSU 30V before this thing kick started at a stable 15.9982MHz.
I removed the top 10nF cap and one 470pF (mine was a different value anyway) from ground., leaving one floating…(aerial!?). So touchy! Just connecting the probe ground can stop it..
17V gives a 1Vpp sine wave – if you don’t move anything!: