Primary receiver. The circuit is very
similar to that of a NSF O40 made in 1923.
Sloping black ebonite control panel and oak cabinet.
Classic model in the shape of a lectern.
Sockets for antenna and earth are
situated at the top of the control panel, left and right
of the two valves. Below the valves, a double coil
holder for swinging coil tuning, a rheostat and a tuning knob with fine tuning.
The sockets on the left are used for plate and filament
voltages; the sockets on the right are for the headphone(s).
The radio was adapted for use with 1
volt valves. Batteries for filament and plate voltages
were placed inside the cabinet, but this was not the way
the radio was intended to function. The design is based
on 4 volt tubes with
a rechargeable lead acid battery
for the filament and a 50 volts battery
for the plate voltage.
The tube set is unknown.
Presumably two A406s.
37 × 23,5 × 21,5 cm
Click on a valve for more information.
Click on the circuit to enlarge.
What was broadcast in 1925?
Listen to "Rose
Marie" played by the Belgian-Dutch
formation "The Excellos Five",
Louis de Vries (tp), Henri van den
Bossche (tb), Alphonse van Asbroek (cl, s), Joop de Leur
(p), Bob Kierberg (dr, ld), recorded in Berlin, December 1925
The receiver was made with
rectangular wire. It was adapted for use with 1 volt
valves with a side connection. By doing this, the
batteries could be placed inside the cabinet. A small
battery for the grid bias voltage was placed near the
Habana transformer (it was already removed before taking this
The batteries were removed, the telephone
condenser was repaired, two missing connections were added and
the grid leak resistor was replaced.
Deze pagina is voor het laatst bijgewerkt op
zaterdag 27 april 2019