Upgrading DAB+ - A new idea for old radios
A tube radio
appeals the fan with good sound reproduction, the tube technology, a
stylish housing and elaborate details inside and outside. You can enjoy
listening your favorite station.
Digital radio
has in combination with undisturbed sound quality the advantage of a
large choice of stations. Now an accessory is available that provides
DAB+ reception with station
tuning via the existing scale. It is
mounted in place of the mixer tube and does not require circuit
modifications. When the accessory is inserted digital radio is
received, when the
original mixing tube is inserted everything is as it
was before.
The solution is simple. A printed
circuit board incorporates a DAB+ receiver, an oscillator that is tuned
from the existing FM or AM oscillator circuitry and is used
for tuning
the digital receiver, and a generator with AM or FM modulation
capability for the radio's IF. The power supply is mainly drawn from
the anode voltage.
The needed tube socket is contained in the price.
The printed circuit board can be
equipped with different tube sockets, for given intermediate
frequencies and can be adapted for nearly all mixing tubes. As some
sockets have become rare it may be necessary that you send an old tube
with the required socket. AC and DC supplied radio models ('Allstrom')
can also be upgraded
for DAB+ due to the use of an insulating antenna
transformer.
It is possible to upgrade AM and FM
type radios.
Upgrading an audion type radio (e.g.
'Volksempfänger'), a dual-circuit or triple-circuit radio type is
possible but often it cannot be done with just replacing a tube
but
requires additional circuit changes. The required modifications depend
on the circuitry of the specific radio.
With this solution the oscillator
frequency is taken from a metallic cap over the FM mixer tube. Supply
voltage, audio frequency and control voltage for the tuning eye
are routed via an intermediate adapter at the EABC80 socket.