Little Princess

The Little Princess portable radio, first introduced in 1937 and still referenced in 1947, stands out as an advanced, compact, battery-operated receiver manufactured by both Peto Scott Co. Ltd. and BTS, London, with identical technical specifications and branding.

Technical Features

• Circuit Type:
• 4-valve (tube) TRF (Tuned Radio Frequency) with regeneration, based on the screened grid principle, was a common design for portable radios of the late 1930s.
• Valves: Four British valves, including a Hivac-Harries output tetrode, which was notable for its high audio output at minimal high-tension (HT) current.
• Speaker: 7-inch (17.8 cm) permanent magnet moving-coil speaker, providing robust audio for a portable set.
• Aerial: Self-contained frame aerial, with optional terminals for connecting an external aerial and earth for enhanced reception.
• Power Supply: HT (High Tension): 90V battery, with a remarkably low current consumption of 6–6.1 mA, allowing for extended use.
• LT (Low Tension): Accumulator (rechargeable battery) for valve filaments, providing up to 30 hours of listening per charge.
• Batteries supplied: Oldham LT, HT, and GB (grid bias) batteries.
• Frequency Coverage:
  • Medium Wave (MW): 200–550 metres (545–1500 kHz)
  • Long Wave (LW): 1000–2000 metres (150–300 kHz)
• Controls:
  • Combined volume and reaction (regeneration) control, using a special dual-action potentiometer for both AF and HF gain.
  • Large tuning knob, off/on and wave-change switch, all grouped around a recessed dial with station names.
  • Headphone jack for private listening, a rare feature for portables of this era.
• Turntable Feature: The radio is mounted on a ball-bearing turntable, allowing it to be easily rotated for optimal directional reception or for the listener's comfort.
• Case and Dimensions:
  • Wooden case, covered in blue Morocco grain leatherette for durability and style.
  • Size: 11.75 in (W) x 9.75 in (H) x 7.5 in (D) (298 x 248 x 191 mm)2.
  • Weight: Approximately 17–18.5 lbs (8.4 kg).
• Performance:
  • Guaranteed to receive at least 25 stations under typical conditions.
  • Excellent sensitivity and selectivity, with the ability to tune in foreign stations even in urban environments.
  • Output power up to 1 watt with strong stations or an external aerial.

Additional Noteworthy Features

• Aesthetic and Portability: Compact, attaché-case size, with a visually appealing design and easy portability.
• Battery Life: Designed for long operation between charges, making it suitable for outdoor or travel use.
• Price:
• Initially retailed at 8 guineas, later reduced to 6–7 guineas as per period advertisements.

Here you find 14 models, 8 with images and 0 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from BTS (B.T.S.) British Television Supplies; London