TUBE ML-5681

The ML-5681 is a compact, general-purpose, high-power electron tube designed for operation at frequencies upt to 110 Mc. It is a coaxial-terminal, water- and forced-air-cooled triode capable of approximately 50 kW output at 110 Mc in cathode-drive circuitry with 10 kW driving power. Maximum ratings of 9 kVdc plate voltage and 90 kW plate input apply at frequencies up to 110 Mc; increased ratings of 15 kVdc plate voltage and 150 kW plate input are permissible at frequencies up to 30 Mc. The ML-5681 has basic design features which make it suitable for use over a wide range of power and frequency in high-power AM, FM, and TV broadcasting, particle accelerator, and dielectric and induction heating services. This tube is ideally suited to cavity operation, and its low plate impedance makes it advantageous for broad-band service. Other features include high-conductivity glass-to-metal seals, sturdy electrodes, integral anode water jacket, quick-change water coupling, and heavy-wall copper anode designed to dissipate 75 kW. All electrodes mount directly from heavy copper rings, resulting in a structure which is electrically and mechanically superior to the conventional types of water-cooled electron tubes. The large-diameter seals provide increased strength and freedom from excessive heating. The cathode is a multistrand, thoriated-tungsten filament, completely balanced and stress free throughout life. The grid is capable of unusually high heat dissipation, contributing to maximum stability of tube performance and circuit operation.