Description  The X79 is a triode hexode frequency changer or mixer. The triode control grid is connected internally to the oscillator injection grid (g3) of the hexode.
Manufacturer Marconi
Country of Origin *
Introduction Year 1950

DATASHEET

Description  The W77 is a miniature variable μ pentode designed to operate at HF. This suggests radio frequency amplifiers as well as intermediate frequency amplifiers.
Manufacturer
Country of Origin England
Introduction Year 1949

DATASHEET

Description  The 6F18 is a variable μ HF pentode for use in broadcast receivers at HF or IF.
Manufacturer GEC
Country of Origin England
Introduction Year 1956

DATASHEET

Description  The UBC81 small double diode triode was designed for signal demodulation and AGC detection in universal mains domestic equipment. The triode section could be used for a first stage of amplification after the detection process.
Manufacturer Philips Miniwatt
BEL
Country of Origin Holland

India

Introduction Year 1954

DATASHEET

Description The U10 directly heated full wave rectifier has an internal coating on the upper part of the envelope. A close look shows that the valve has cathode tubes that are internally strapped to one side of the filament. Our other classic enveloped U10 has a hairpin of oxide coated ribbon as the emissive surface. The original U10 came with a balloon envelope.The maximum reservoir capacitor is not quoted, but at 60 mA maximum output current the U10 was clearly designed for broadcast radio reception in 1930s all mains sets. The 4.0 Volt heater is characteristic of the 1930s British heater standard.
Manufacturer *
Country of Origin *
Introduction Year 1930

DATASHEET

Description  The EZ80 full wave rectifier was found in many broadcast receivers and domestic audio equipment.Suited to the task, at 90 mA maximum current and with a required series resistance of 300 ohms to reduce the initial surge in charging the maximum 50 µF reservoir capacitor, each anode would conduct in turn when connected to either end of a grounded centre tapped mains transformer.
The EZ81 is pin compatible but rated at 160 mA.The anodes are mounted vertically and at right angles over a common cathode. The anodes are identical but one is mounted upside down so they both fir the cathode.

The anodes form a cross to give maximum area for heat dissipation.

Manufacturer BEL
Country of Origin India
Introduction Year 1954

DATASHEET

Description  Mullard describe the EF41 as a variable μ RF pentode for use as an RF or IF amplifier.
In the literature Mullard state that although pins 3, 4 and 7 are internally connected together, it is recommended that the external cathode connection be made to pin 7 as this point offers the lowest connection inductance.
Manufacturer Philips Miniwatt
Telefunken
Country of Origin Britain

*

Introduction Year 1947

DATASHEET

Description  The EBF89 features two signal diodes and a variable μ pentode in the one envelope and sharing a common cathode. The diode anodes are small plates placed either side of an extended cathode tube.The variable μ characteristic is indicative of a device designed to have its gain controlled by an AGC system. This places this valve in service as a final IF amplifier and detector. The high impedance of the pentode supports the case for use with a tuned circuit connected to the anode.
Manufacturer BEL
Country of Origin India
Introduction Year 1958

DATASHEET