Vince,

Making my own pot now.. testing with letters as well. How far down in the copper is your F1 ingraved..? And how long is it from the bottom of the ingraved part to the bottom of the hole pot?

My testpot is 20mm copper in the bottom before the ingraved part is 15mm.. = 35mm.. I think this is to much.. need to get som LN2.

Thanks is advance.