Philips 730A

Philips 730A

Brand and type/origin: Philips 730A - Holland 1930

Cabinet: Plywood with different veneers. Black painted at the rounded edges and inside the dial window. As far as I know, the first Philips with a built in speaker. The speaker grille, cut out with a jigsaw it seems, shows the Philips logo of the era.

Tubes: E462 (1st HF) - E446 (2nd HF) - I253 (det.) - E428 (1st AF) - E443H (output). The 1805 is a directly heated full wave rectifier. None of these are the original types, except the 1805. The E446 is a pentode tube, where a tetrode tube was intended. But it works without modifications. All tubes are a few years younger than the original ones, but still we talk about "old grey hair" types from the same era.

Power: In 12 steps from 103 up to 253V - AC only. This again shows that the mains supply voltage in the early days of electricity varied from village to village. Often DC only was delivered, in that case you needed to buy a DC powered radio, or a universal AC/DC radio.

Bands: Medium waves 150-550 m and long waves 700-2000 m.

Controls: Volume control is obtained by varying the bias voltage of the first HF stage. A pickup can be connected but should have its own volume control. Only two knobs: Volume-on/off and tuning/bandswitch.

Condition: Despite its monthly shot of furniture oil, the veneer is loosening at some edges. So far woodworm stayed away.

Working: OK with a good antenna and grounding. The radio easily picks up noises from fluorescent lamps and computers. The speaker has a permanent magnet and sounds a bit metallic. Selectivity and sensitivity don't reach nowadays standards of course, but overall it plays satisfactory.