• Country
• People's Republic of China

• Manufacturer / Brand
• Tianjin 天津渤海无线电厂 Tianjin Bohai Radio Factory; Tianjin (N)

• Year
• 1968 ??

• Category
• Broadcast Receiver - or past WW2 Tuner

• Radiomuseum.org ID
• 178103

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

• Number of Transistors
• 7

• Semiconductors
• 3AG51E 3AG51D 3AG51D 3AX31A 3AX31A 3AX31B 3BX01 2AP9 2AP9

• Main principle
• Superheterodyne (common); ZF/IF 465 kHz; 3 AF stage(s)

• Tuned circuits
• 5 AM circuit(s)

• Wave bands
• Broadcast and Short Wave (SW).

• Power type and voltage
• Dry Batteries / 6 Volt

• Loudspeaker
• Permanent Magnet Dynamic (PDyn) Loudspeaker (moving coil)

• Material
• Plastics (no bakelite or catalin)

• from Radiomuseum.org
• Model: Haiou 海鸥 705 - Tianjin 天津渤海无线电厂

• Shape
• Very small Portable or Pocket-Set (Handheld) < 8 inch.

• Dimensions (WHD)
• 180 x 90 x 40 mm / 7.1 x 3.5 x 1.6 inch

• Notes
• The model Haiou 海鸥 705 (Seagull) has the following key features 主要性能: Frequency range 频率范围: broadcast band 535 - 1605 kc and SW 3.9 - 12 mc. Sensitivity 灵敏度: < 1.5 mV/m (1 mV/m). Selectivity 选择性: not given. Electric power consumption 电源消耗 at zero signal 零信号: 14 mA, at max. it is 60 mA. Set audio output 额定功率: 100 mW (250 mW). The IF is 465 kc. Loudspeaker impedance is 8 ohm. 2 diodes.

• Net weight (2.2 lb = 1 kg)
• 0.460 kg / 1 lb 0.2 oz (1.013 lb)

• Mentioned in
• 03-Transistor Radio Circuit Manual 1981 August (1 of 5) (page 209.)

• Literature/Schematics (1)
• 02-Radio Manual unknown date, 380 pages (page 89, drawing 202.)

• Author
• Model page created by Ernst Erb. See "Data change" for further contributors.

• Other Models

• Here you find 25 models, 16 with images and 23 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Tianjin 天津渤海无线电厂 Tianjin Bohai Radio Factory; Tianjin (N)