There's
an article about this radio in the Dutch radio-collectors magazine.
It says that the estimated amount of radios produced is 500. Probably
4 are left over nowadays.
Well, now no.5 has turned up with a much higher
serial no. On the radios tag is only space for 3 digits for the serial
number!
Produced:
Hilversum, the Netherlands 1926
Cabinet:
Solid mahogany,
dimensions 50x27x23 cm.
The front is made of ebonite.
This is simple rubber in fact, but for the vulcanisation process much
more sulphur than normal was added.
This resulted in a material hard
and stiff like wood and good isolation properties.
Probably a wooden
front wasn't suitable because of its ability to absorb moisture, thus
giving bad isolation. The blackness comes from a certain amount of soot
which was added in the rubber mixture.
Tubes:
Three 4-pin triodes: A415, A415 and B405 as output.
Power:
Three batteries: 4V, 90V and a C-battery (negative grid bias) which
was adjustable by taps up to 20V.