">

">

">

">

2M57 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

Capacitors

Drawing from patent application