TRF receiver for AC

Four-valve AC receiver with a built-in loudspeaker. Erres called the radio "Singer on the wall".

   Otto van Tussenbroek

Rigid "Haagse Stijl" design by Otto van Tussenbroek (1882-1957).
The cabinet is made of oak, the front, with brown speaker cloth (original but fainted, is made of black crackle painted aluminum (upper part) and steel (lower part).
This radio has a gramophone connection that is not present in earlier models (see picture below). Date stamp on one of the capacitor blocks: January 10th, 1931.
Made by Van der Heem & Bloemsma, The Hague.
The knobs from left to right: primary tuning, feedback, secondary tuning, wave length slide switch. Circular scales (0-100)
There is also a rare battery version of this radio. It uses the valves A442, A415 and B443.
Some sources mention a E452T instead of a E442. The E452T was introduced in 1931. The 1500 ohm volume control suggests a E442. The KY108 does have a E452T and a 3000 ohms volume control.
Data Valves Other information
Serial number: 67032/67996
Produced: ± 2400
Dimensions: 37,5 × 49 × 18,5 cm
Made in: 1930-1931
Purchased in: 2005/2006
Voltage: 220 Volt ~
Click on a valve for more information

Circuit
  Leaflet (in Dutch)
  Restoration report

What was broadcast in 1930?
 

Listen to "Hallo, hallo, hier Hilversum" sung by Kees Pruis, recorded in 1930

Back
Date stamp on one of the condenser blocs: January 10th, 1931.
Back
With oak and aluminium back panels.
Side view
Showing the tiny volume control knob.
Connections
Above: KY107 66763 without gramophone connection
Below: K107 67996 with gramophone connection (this feature was added in 1931)
Assembly of the Erres KY107 in the assembly room of Van der Heem at  Stortenbekerstraat, The Hague
Picture in Radio-Expres, September 12, 1930 Advertisement for the Philips 4000 l.f. transformer that was used in the KY107 in Radio-Expres, September 19, 1930
The Erres KY107, advertisement, 1930
St. Nicholas recommending the Erres KY107
holding the 11 kg receiver with one hand, seemingly without difficulty.  Advertisement by Fa. Lammers & Vaartjes, Leeuwarden, Fen Fryske Groun, December 1930