• Country
• Belgium

• Manufacturer / Brand
• SBR Société Belge Radio-Electrique, Bruxelles

• Year
• 1922

• Category
• Radio module pre 1926 (not a part, not a key)

• Radiomuseum.org ID
• 228393

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

• Number of Tubes
• 2

• Valves / Tubes
• TM TM

• Main principle
• Detector with Vacuum Tube (Valve), no tuner

• Wave bands
• - without

• Details
• Converter

• Power type and voltage
• Storage and/or dry batteries / 4 Volt

• Loudspeaker
• - - No sound reproduction output.

• Material
• Wooden case

• from Radiomuseum.org
• Model: Radio-Puzzle RPF - SBR Société Belge Radio-

• Shape
• Tablemodel, Box - most often with Lid (NOT slant panel).

• Dimensions (WHD)
• 190 x 190 x 200 mm / 7.5 x 7.5 x 7.9 inch

• Notes
• • This unit is part of the so-called "Radio-Puzzle" which is modular in conception by placing every stage in a different module. It could be configured not only as a radio with different principles but also as telegraphy receiver and writer or as measuring equipment.
  • By combination of different units, one gets a complete radio or other application.
  • All connections are made with wires in clamping screws.
  • The clamping screws for the filament "A" battery and the plate voltage "B" battery are placed at the same height/depth so that they can be easily interconnected. The whole powerline setup is made as a daisy chain.
  • These units were initially manufactured and commercialised by S.I.B. from 1920 on before SBR took over the retailing under their own label in 1922.
  • Used coils on these units are Disco-self 1922 or the preceding SIB Disco-Self 1920. They are optionally mounted on the side panels of units A, B and E. The obtainable frequency range with those coils was approximately 13kHz (23000m) to 1,75MHz (170m).
  • The following modules of the Radio-Puzzle are known:
    • RPA = Tuning module and optionally a crystal detector. Despite the fact that this unit doesn't need power, it has power connectors to pass along the current to the next unit;
    • RPB = Tuning module with RF amplifier and detector;
    • RPC = RF amplifier with regenerative feedback or an autodyne with a "Compensateur"¹ and optionally a detector;
    • RPD = RF amplifer with RC² interstage coupling (autodyne amplifier together with RPC). However, this unit can be used as LF amplifier stage also;
    • RPE = LF amplifier with interstage transformers;
    • RPF = Tube detector (not an amplifier) to drive a morse writer or a repeater morse key. Driving power for the following relais after this unit comes from the preceding LF amplifier module (see schematic and explanation at the bottom of this page);
    • RPG = Variable coupling unit for 2 disco-self coils from which 1 has fixed position on the preceding unit RPA, RPB;
    • RPR = Variable coupling unit for 3 disco-self coils from which 1 has fixed position. It could be used to make a regenerative circuit by variable induction.

  Alternative for TM tubes: Marconi_R

  ¹ Compensateur: the differential variable capacitor to control the positive and negative feedback. Not a butterfly capacitor.
  ² Resistor and capacitor.

• Price in first year of sale
• 203.00 BFr

• Author
• Model page created by Dirk Bladt. See "Data change" for further contributors.

• Other Models

• Here you find 711 models, 659 with images and 384 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from SBR Société Belge Radio-Electrique, Bruxelles