IDEEZET Radio tube by PHILIPS

Light bulb factory Philips manufactured this triode lamps in the period mid-1918 to early 1923. Idzerda had the exclusive right to sell to amateurs for fl. 12,50. The lamps sold by him have PHILIPS IDEEZET stand on the glass.
Technical Information:
The housing is a glass tube with a Mignon fitting on both sides. Respectively, for connection of the filament and for the grate and the plate. The electrode system is formed by two planar anode plates and two zigzag curved gratings. The two plates and the two grids are mutually connected with each other in the fitting. With the exception of the subsequent ones, the lights were low vacuum and filled to a certain pressure with argon gas.