International All-Wave Superheterodyne

Introduced at the August 1934 Olympia Radio Show (Stand 113) and demonstrated at The Radio Centre (Haymarket, London), this high-grade receiver was engineered to cover ultra-short, short, medium, and long wavebands 14-2,000 metres across four continuous bands.

The set employs a two-chassis design—separating the tuner/RF section from the audio and power supply units—to minimize hum and interference. It was offered as a Table Model (£35) or integrated into a console Radiogram (from 50 guineas).

Technical Specifications:

• Circuit Principle: Superheterodyne; 2 I.F. stages using heavy Litz-wire coils with double-tuned transformer coupling.
• Wavebands: 4 bands covering 14-2,000 metres (150 kHz- 21.4 MHz), calibrated in kilocycles and wavelengths with individual dial scales.
• Valves: Universal valve lineup including Octode frequency changer, Double Diode 2nd detector (supplying AVC voltage), Variable-Mu Pentode audio stage, 120 mA rectifier, and a Barretter tube for current regulation.
• Power Type & Voltage: Universal Operation — AC or DC Mains. Includes H.F. filter chokes on the mains input.
• Loudspeaker: Moving Coil Loud Speaker featuring 15-watt field excitation.
• Controls & Features: Dual-speed (fast/slow) tuning control, band-specific dial illumination, continuously variable volume and tone controls, and integrated gramophone pick-up switch (built into the wave-change switch).

Here you find 4 models, 2 with images and 0 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from Allwave International Radio & Television, Ltd.; Kent