Four valve
homodyne (direct conversion*) battery receiver
In
oak cabinet with doors. The doors are decorated with
coromandel wood.
At the top isa hinged lid withsnap closure.
The knobs from left to right:
rheostat for the mixer valve with the text "zwak/sterk"
("weak/strong"), antenna tuning, wave length switch with
two push/pull switches above, the upper one for the scale lights
(remarkable for a battery set) and the lower one
forswitching off thefilament currentcircuitof the valves,
followed by oscillator tuning and reaction control (as a
matter of fact fase
control of the oscillator). This remarkable
circuithasnot often been
usedincommercially manufacturedreceivers.
*) A direct-conversion receiver (DCR),
also known as homodyne, synchrodyne, or zero-IF
receiver, is a radio receiver
design that demodulates the incoming radio signal
using synchronous detection driven by a local oscilator
whose frequency is identical to, or very close to the
carrier frequency of the intended signal. This is in
contrast to the standard superheterodyne receiver where
this is accomplished only after an initial conversion to
an intermediate frequency. Most modern radios use direct
conversion. Using digital techniques, this design works
a lot better than in the 1920s and 1930s.
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