• Country
• Belgium

• Manufacturer / Brand
• Siera; Belgien

• Year
• 1936

• Category
• Broadcast Receiver - or past WW2 Tuner

• Radiomuseum.org ID
• 98710

Click on the schematic thumbnail to request the schematic as a free document.

• Number of Tubes
• 5

• Valves / Tubes
• EK2 EF5 EB4 EL3 EZ3

• Main principle
• Superheterodyne (common); ZF/IF 128 kHz; 1 AF stage(s)

• Tuned circuits
• 7 AM circuit(s)

• Wave bands
• Broadcast, Long Wave and Short Wave.

• Power type and voltage
• AC/DC-set / 110; 125; 145; 200; 220; 245 Volt

• Loudspeaker
• Permanent Magnet Dynamic (PDyn) Loudspeaker (moving coil) / Ø 21.5 cm = 8.5 inch

• Material
• Wooden case

• from Radiomuseum.org
• Model: S4U - Siera; Belgien

• Shape
• Tablemodel, high profile (upright - NOT Cathedral nor decorative).

• Dimensions (WHD)
• 340 x 400 x 270 mm / 13.4 x 15.7 x 10.6 inch

• Notes

• This is basically the same radio as model S4A, with a different transformer and adapted power section to accomodate the vibratory convertor with reference number 28.891.460.

  The Siera vademecum 1932-1946 mentions the same tube line-up for types S4A and S4U. The Philips near equivalent for type S4U, being type 456U -20, only carries a schematic for the vibrator converter while referring to model 456A for the schematic of the radio itself. When fed by a DC mains, the power must pass via the converter. and not directly into the radio as usual with a AC/DC set.

  3 Band reception:

  • LW: 725 - 2000 m.
  • BC: 198 - 585 m.
  • SW: 16 - 51 m.

  Tuning scale light bulb type: 8045D (6,3V, 320mA).

  Loudspeaker Philips type 2369. Connectors for second loudspeaker and for pick-up. 

• Net weight (2.2 lb = 1 kg)
• 12.2 kg / 26 lb 14 oz (26.872 lb)

• Price in first year of sale
• 2,300.00 BFr

• Mentioned in
• - - Manufacturers Literature (Siera memento of tubes and models 1932-1946)

• Literature/Schematics (1)
• -- Original-techn. papers. (Model Siera S4A)

• Literature/Schematics (2)
• Trader Service Sheet (suppl. of Wireless & El. Trader, etc.) (594)

• Author
• Model page created by John Koster. See "Data change" for further contributors.

• Other Models

• Here you find 456 models, 414 with images and 188 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Siera; Belgien