The 445 Triode from De Forest has many equivalents and is a triode from the early 1930s.
The locating pin for the bayonet base can be seen on the base cap to the right. The anode has a small front to back dimension and is wider in face view.
The mica holds the tops of the electrodes in place. The filament can be seen as an M shape with two tensioning springs holding the two top loops of the oxide coated wire.
The grid supports are notched to hold the wire. The blackened anode is stitched together and held by two side supports.
The balloon envelope is 54 mm in diameter and, excluding the UX4 base pins, is 116 mm tall.
References: 3002. Type 445 was first introduced in 1931. See also1931 adverts.
