The QQZ04-15 is a quick heating VHF transmitting double tetrode. Each anode can dissipate 8 Watts in intermittent service or 6 Watts for continuous operation. It was designed for mobile VHF transmitters in the VHF region up to 186 MHz. Use was as a Class C output stage but it could also be used for an oscillator or frequency multiplier.
One anode seen face view. The anode is blackened to act as an efficient radiator and ribbed to give dimensional stability to the thin sheet nickel anode.
The design is of the European pattern with a central cathode, two single sided control grids, a common screen grid and common beam plates.
The wide glass tube envelope is 27 mm in diameter, and excluding the base pins is 80 mm tall.
Reference: Datasheet. Type QQZ04-15 was first introduced in 1964.