Oven Magnetron

Oven magnetrons don't normally rate as a collectible but this one is somewhat
interesting - the 2M57 - first oven magnetron to assume the well recognized
modern format - you can see some features in this tube that will be lost as
they go into really big scale production - inside the cathode box can be
seen 2 ceramic insulators supporting the RF chokes - and the feedthroughs
use proper ceramic feedthrough capacitors which are bolted to the case -
unlike the modern molded connector with internal capacitors. The 2M57 is
also somewhat bigger than most later magnetrons. This device uses a 12
segment resonator - which was continued for a few more models, but most
recent production devices use a 10 segment resonator.. The label on the side
notes US patent 3809950 - this is the first patent where magnetrons of the
modern design can be seen.

Cathode Box
Drawing from patent application