The 7508 is a special quality double triode designed for use as a multivibrator, cathode follower, VHF amplifier and VHF cascade amplifier.
Special features of the valve are: long life, rugged construction, high transconductance, low noise and low microphonic sensitivity. The base pins are gold plated.
Amperex were known for professional video recorders and this may have been used in such a studio product.
Is this logo a quality symbol? Note the etched USA near the base. Does this suggest that this valve was made for Amperex rather than by them.
The triode sections have an electrostatic screen between them. The tab and pin connection is in the foreground.
The anode has bulk to distribute and radiate heat but the working part of the anode is the small pressed rectangle.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 48 mm tall.
Reference: Data-sheet. Type 7308 was first introduced in 1962. See also1962 adverts.