The 4D32 is a rugged beam tetrode for RF power amplifier service in mobile or airborne systems. As a Class C RF amplifier full ratings apply into the low VHF at 60 MHz. 100 Watts is possible.
This example is marked as a USAF 4D32 - clearly aimed at airborne use with the American military.
As a Class B audio amplifier a pair can deliver 125 Watts output.
The 4D22 differs only in heater rating. It has a centre tapped heater for operation on 25.2 or 12.6 Volt supplies. 12 or 24 Volt vehicle batteries.
The anode has ceramic insulators and several additional fins to aid heat dissipation.
Looking down into the envelope the anode is constructed from relatively thick nickel sheet. Inside the top of the bean plate can be seen.
A closer view.
The cathode tube is a flat rectangle and both grids are wound on substantial copper rods. The screen grid has a heat sink attached. The top screen shields the tops of the grids from the anode support.
The wide glass tube envelope is 57 mm in diameter and, excluding the B7A base pins, is 120 mm tall.
Reference: Data-sheet. Type 4D32 was first introduced in 1945. See also1945 adverts.
