The 2C39A is of planar design and disc seal construction and glass envelope parts.

The dominant feature is the large external heat sink fins connected to the anode. This device would be used in a cavity as the RF Power stage of a transmitter into the low microwave region.

The apex of the cone houses the heater and cathode assembly. The grid is a circular metal mesh that extends to the metal cylinder around its circumference thus providing isolation between input and output. The anode is a solid bar connected to the heatsink. In operation the valve would normally be force air cooled, but water cooling is not unusual. In the latter case the heatsink assembly is held in watertight tube of Copper or Brass. We have such a holder in the museum.

The planar envelope is 32 mm in diameter and, excluding the IO base pins, is 47 mm tall.

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	mAa	f.max	Pout
	6.3	1.0	1000	100	2400	20W

Thanks to Frank Philipse for supplying the above datasheet

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This exhibit was last updated on 02 July 2007 {find valves by name}