The QQV04-16 is a European pattern VHF double tetrode and the specification dates to 1961. The structure is miniaturized and this valve was specified for amplifier, oscillator or frequency multiplier stages at UHF. In fact full frequency rating applied to 900 MHz and an output of 7 Watts.
Unlike the classic format of these valves as is seen in QQV03/20A with vertical anodes and twin anode top caps, this valve has a very much smaller structure that is placed horizontally in the envelope.
The connections are given in the data-sheet. The QQV04-16 uses a B8A base pin circle with separate anode pins.
A close-up of the electrodes reveals the anodes on either side of the central cathode assembly. The common screen grid is clearly visible but the single sided control grids are too fine to be visible. The cathode is oxide coated and the heater is centre tapped so that it can operate at 6.3 Volts as well as 12.6 Volts. This is typical for the QQ family of double beam tetrodes.
The wide glass tube envelope is 44 mm in diameter, and excluding the base pins is 48 mm tall.
References: Datasheet & 1040. Type QQV04-16 was first introduced in 1961.