The 7586 was the first production Nuvistor type and was introduced in 1959. The Nuvistor from RCA was a form of triode for use at VHF and built into a metal case just larger than a transistor. The base is ceramic sealed to the metal case and five fine pins, on a 12 pin grid, form the connections and the electrode supports internally. A special base is required.
The Nuvistor is built as a series of co-axial electrodes but they are all very small, and small inter electrode capacitances result. Thus the high frequency of operation. Unlike the transistors of the time the Nuvistor had the overload and intermodulation characteristics of the valve, which were superior to the transistors of the day.
Our specimen came from a Tektronix dual trace oscilloscope 'Y' amplifier.
The pins are protected by the extended case, that also acts as a guide into the base for the fragile pins.
The RCA name and the curved bottom plates that protect the connecting pins.
The ceramic insert with both base pins and the ends of the internal supports.
The thin metal tube envelope is 9 mm in diameter and, excluding the base pins, is 20 mm tall.
Reference: Data-sheet. Type 7586 was first introduced in 1959.