Direction Finder Marconi-Bellini-Tosi Type No 11F
- Great Britain (UK)
- Manufacturer / Brand
- Marconi's Wireless Telegraph Co. Ltd.
- 1922 ??
- Broadcast Receiver - or past WW2 Tuner
- Radiomuseum.org ID
- Number of Tubes
- Power type and voltage
- Storage and/or dry batteries
- Wooden case, TUBES VISIBLE.
- from Radiomuseum.org
- Model: Direction Finder Marconi-Bellini-Tosi Type No 11F - Marconi's Wireless Telegraph
- Tablemodel, Box - most often with Lid (NOT slant panel).
- Dimensions (WHD)
- 440 x 470 x 300 mm / 17.3 x 18.5 x 11.8 inch
The Direction Finder for professional use Type No. 11F is similar to Type 11 and Type 11A but has one tube more. We are not sure about the valve types.
"BTDF was invented by a pair of Italian officers in the early 1900s, and is sometimes known as a Marconi–Bellini–Tosi after they joined forces with the Marconi Company in 1912. BTDF was the most prevalent form of naval direction finding from the 1920s to well into the 1980s and was used as a major part of early long-distance air navigation systems from the 1930s until after World War II. BTDF systems were also widely used for military signals intelligence gathering."
From mhs.ox.ac.uk collections:
"Marconi' Direction Finder Type 11F, with assorted vertical and sloped ebonite panels, in a dovetailed teak case. With seven DEV/Q valves, note magnifier switch, and filaments control upon the upper vertical surface. With glazed-top radiogoniometer (scale 0-360) and tuning condenser dial (scale 0-10), parallel condenser switch, DF sense switch, upon central sloping ebonite and white plastic(?) panel. With earthing relay and calibrating choke ebonite sections upon lower vertical section. With four plugs, two nickel-plated terminals (marked "DF1", "DF2"), and a bank of five nickel-plated terminals (marked "EARTH", "PORT", "STBD.", "AFT", "FORE" respectively) on left-hand side exterior surface of the case. With a bank of five nickel-plated terminals (marked "SWITCH", "4V+", "6V+", "COMM", "HT+" respectively) upon right-hand side exterior surface of the case."
- Model page created by Ernst Erb. See "Data change" for further contributors.
- Other Models
Here you find 90 models, 88 with images and 16 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from Marconi's Wireless Telegraph Co. Ltd.