In metal housing.The first series were made of black painted
copper, later receivers were made of a different metal.The top is Bakelite.With
the help of the crystal and two nickel-plated sliding
levers on the front and rear (Antenna and Detector) the
device can be tuned.
Reception on medium wave.
The range was between 30 and 60 km, when
using a long antenna.
To receive maritime transmissions, a maximum range of
195 to 975 km was specified, depending on the height of
the antenna used and the strength of the transmitter.
A two-tube amplifier, the Federal Junior
Amplifier No. 20, could be included some time later.
This enabled playback
using a loudspeaker and also further removed stations
could be made audible.
In March 1922 the first ads for the
Federal Jr. appeared.