Sensibly equivalent¶ to:
The M8157 is a special quality version of the commercial QV04-7. The M8157 is a single beam tetrode for transmitter use up to the low VHF region.
The design is all glass as were all of the B9G based valves. The valve would have been used for driver and frequency multiplier stages as well as for low power transmitters. It was designed for class C service.
The makers code is stamped into the aluminium skirt that holds the base plate and spigot on to the glass envelope.
The wide glass tube envelope is 33 mm in diameter and, excluding the B9G base pins, is 57 mm tall.
Reference: Datasheet. Type M8157 was first introduced in 1957.
Absolute Maximum Operating Conditions¶
Updated March 29, 2013. shape:wide.glass.tube construction:all.glass type:beam.tetrode age:1950.1960 base:b9g heater:6.3v pins:9 pin:1.h pin:2.a pin:3.g2 pin:4.g2 pin:5.bp.s pin:6.k pin:7.g1 pin:8.bp.s pin:9.h