• Year
  • 1947/1948
  • Category
  • Broadcast Receiver - or past WW2 Tuner
  • Radiomuseum.org ID
  • 184896

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

 Technical Specifications

  • Number of Tubes
  • 4
  • Main principle
  • Superheterodyne (common); ZF/IF 457.5 kHz; 1 AF stage(s)
  • Tuned circuits
  • 6 AM circuit(s)
  • Wave bands
  • Broadcast only (MW).
  • Power type and voltage
  • Alternating Current supply (AC) / 40-50 Hz, 200-220; 221-240; 241-250 Volt
  • Loudspeaker
  • Permanent Magnet Dynamic (PDyn) Loudspeaker (moving coil) / Ø 5 inch = 12.7 cm
  • Power out
  • 1.5 W (max.)
  • Material
  • Bakelite case
  • from Radiomuseum.org
  • Model: 46B Ch= A436B/S - His Master's Voice HMV, H.M.V.
  • Shape
  • Tablemodel without push buttons, Mantel/Midget/Compact up to 14
  • Notes
  • Cabinet colours: walnut, walnut with ivory grille, green with ivory or all cream.

    CIRCUIT DESCRIPTION (from service manual)

    This model is a four-valve mains operated broadcast superheterodyne. It normally operates from a self-contained loop aerial which is provided with primary coupling for connection of an aerial/earth system. The primary circuit incorporates a loading inductance and damping resistor in order to reduce signal frequency tracking error to a minimum when an external aerial/earth system is connected.

    The signal frequency tuned circuit is connected to a Pentagrid Converter; Oscillator voltage on the signal grid of this valve is neutralised by means of a small wire capacitor connected from oscillator plate to signal grid. The oscillator inductance is permeability tuned and has a fixed padder capacitance.

    The converter valve is transformer coupled to the pentode section of a duo-diode pentode valve, the output of which is in turn transformer coupled to the demodulator diode, the other diode being capacity coupled to the plate circuit and functions as an A.V.C. rectifier. Both I.F. transformers are permeability tuned and have fixed capacitors. A resistive network across the H.T. filter choke and series resistor provides delay voltage for the A.V.C. diode and standing bias for the converter valve. A.V.C. voltage is applied to the converter valve whilst the I.F. valve is operated with fixed bias. The demodulator circuit is coupled to the potentiometer volume control, the output of which is taken to the grid of the beam power output valve.

    The power output of this valve is limited by operating the screen at a reduced voltage. The output stage is transformer coupled to the voice coil of a permagnetic speaker. A tertiary winding on the output transformer provides inverse feedback voltage which is fed back to the input circuit of the output stage through a tap on the volume control.

    High tension voltage is supplied by a full wave rectifier, the output of which is filtered by a choke in the negative side.

    See also wooden cabinet version, Model 46W.

  • Price in first year of sale
  • 21.50 AUS £
  • Circuit diagram reference
  • Australian Official Radio Service Manual Vol. VI
  • Literature/Schematics (1)
  • -- Original-techn. papers. (Service Manual.)
  • Author
  • Model page created by Stuart Irwin. See "Data change" for further contributors.

 Collections | Museums | Literature

Collections

The model is part of the collections of the following members.

 Forum