131
Item nr.
The pocket tube radio.
| Production | Japan, 1954. |
|---|---|
| Bands | MW (535-1650 kHz). |
| Tubes | 1R5 (converter), 1T4 (IF amp), 1S5 (detector and AF amp), 3S4 (output). |
| Cabinet | Plastic. Size 19x13x5 cm. Weight 1.1 kg. |
| Power | Batt 67.5V and 1.5V. |
| Documents | Schema, User information, both on a sticker in the back. |
The set needs a D cell (1.5V monocell) for the filaments, and a 67.5V plate battery. The battery cost was often mentioned to be the major drawback of battery sets, but how much is it actually? A plate battery is formed of six P-cells at a cost of circa 15 guilders, running some 50 hours, which is 30 cents per hour. The ideal filament battery costs 4 guilders and lasts about 40 hours, which is another 10 cents. The total battery cost is about 40 cents (guilders) per hour. For listening news broadcasts and incidental music works this is quite acceptable, only for using the radio to provide musical wallpaper the cost would become high.
Probably the same radio was sold under different brands: under the brass decal with the name HIGHNESS there is the name Stantex.
| Obtained | 8/1999 from Piet Hoen. |
|---|---|
| Condition | 7. |
| Disposed | Sold 3/2015. |
| Sound sample | PLAY SOUND This short music sample should give you an idea of the quality of the pocket tube set. It plays on a D-cell for the filament, and 6 P-cells (54V) as the plate battery. |
Repair and restoration were not even difficult; I just checked everything I saw and measured against the schema, and after that the radio worked fine immediately.
Though the radio plays best with the original voltage of 67.5V, the radio plays well even when the battery is quite low: the voltage of the four cells I had once connected dropped to about 24 volts, and operation was still good (not at loud volumes). The current draw is then 2 mA only!
Here is an inside view. You can clearly see the package of six 9V blocks supplying B+, and down left is the filament battery. Apparently, B+ batteries were larger in the fifties. The tubes are mounted horizontally and near the top there is a ferrite rod.
