Introduced in 1916, the 'Q' tube is a  triode with widely positioned leads to minimize inter-electrode capacitance. It was a high impedance tube, used primarily as a detector. Like all early Marconi tubes, it was originally made by Edison Swan  but after 1919 by M-OV.

The V24 was a directly heated triode. It was  a development of the 'R' type aimed at improving high frequency performance. Type V24 was introduced in 1916 and was used as an RF amplifier. Filament needs 3 volts at 0.7 Amps with an anode voltage of 24 volts, hence the name V24.