Sensibly equivalent¶ to:
11D3 13DHA CV1419 DDT13 H4D HL/DD/1320
The TDD13 is a mains double diode triode designed for 200 mA heater chains. This suggests universal mains supplies, and the anode voltage of 200 Volts confirms this.
The TDD13 is the same valve but fitted with a Ct8 base cap. It also was introduced in 1935.
The double diode triode would be found at the end of the IF chain in the line-up and would perform the functions of signal and AGC rectification as well as first audio amplification stage feeding the output stage valve.
The classic envelope is 40 mm in diameter and, excluding the B7 base pins, is 100 mm tall.
References: Datasheet & 1043. Type TDD13C was first introduced in 1935.
Absolute Maximum Operating Conditions¶
Updated December14, 2012.