ECH3 Tungsram used/good 1940 era1) ECH3 Tungsram used test good 1940 era Tested on TV 7D U The ECH3 is a triode hexode mixer for broadcast receiver use. The base is the continental side contact type. The oscillator triode has to supply 11 Volts peak to peak for the hexode mixer for correct operation. A year later in 1940 the ECH3 was also available with the IO base and called the ECH33. The classic envelope is 35 mm in diameter and, excluding the Ct8 base pins, is 88 mm tall. Type