The 5763 is a small transmitting beam tetrode valve for HF and low VHF use and is equivalent to the Mullard QV03-12. We also have the 5763 with orange lettering.
The heater is referenced as 6.0 V by RCA, Brimar and Mullard.
John Fielding ZS5JF has sent the following information and the RCA data-sheet.
The 5763 was extensively used as an oscillator, multiplier or power amplifier in HF and VHF equipment. The old Marconi Instruments Q meter variable frequency oscillators used it, also used in the power supply as a series regulator valve. The useful upper frequency limit is about 300 MHz. It was also used as a driver or PA in some early Pye Telecomms VHF mobile radios before being superseded by the twin tetrode QQV03-10 type of valves.
The circular anode contains a flat sided cathode and grids that are flat across the cathode width and rounded at the ends. The screen grid wires are directly in front of each control grid wire.
A closer view of the grid wires.
The anode seam and the origin of the valve - Japan. The original maker name is missing.
The thin glass tube envelope is 21 mm in diameter and, excluding the B9A base pins, is 58 mm tall.
References: data-sheet & 1040. Type 5763 was first introduced in 1949. See also1949 adverts.
