• Country
• People's Republic of China

• Manufacturer / Brand
• Unknown - CUSTOM BUILT: China

• Year
• 2022 ?

• Category
• Service- or Lab Equipment

• Radiomuseum.org ID
• 340849

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

• Number of Tubes
• 1

• Valves / Tubes

• Number of Transistors
• 7

• Semiconductors

• Wave bands
• - without

• Power type and voltage
• Batteries / addl. power jack / AA 2 x 1.5 / USB 5 Volt

• Material
• Plastics (no bakelite or catalin)

• from Radiomuseum.org
• Model: Kailishen Geiger-Müller Counter BR-6 v3.0 - Unknown - CUSTOM BUILT: China

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

• Dimensions (WHD)
• 135 x 40 x 70 mm / 5.3 x 1.6 x 2.8 inch

• Notes

• The Kailishen BR-6 Geiger-Müller Counter is a X-ray, Beta, and Gamma nuclear radiation detector, featuring real-time, mean, and trend dose calculations displayed in µSv/h.

  Specifications

  • Counter tube: J321 energy compensated GM tube (M4011 compatible)
  • Detectable particles: Beta, Gama, and X-rays
  • Energy range: 20 keV~3.0 MeV ± 30% (Cs-137)
  • Sensitivity: 80 cpm/µSv (Co-60)
  • Test accuracy: 0.01 µSv/h
  • Real-time range: 0 - 99.99 µSv/h
  • Real-time error: ≤ 10%
  • Mean error: ≤ 3%
  • Power supply:
    • 2 x 1.5 V dry batteries or 1.2 V rechargeable batteries
    • USB 5 V for prolonged usage of the equipment
    • Note: The user guide is misleading concerning the charging feature, as there is no charger circuitry inside to handle this operation.

   

  Brief technical and operation details

  According to tests and dismantling published by owners, there are at least two different PCB versions of the BR-6 equipment. 

  • An older PCB, available at least since 2019, marketed with the Waysear brand, based on a M4011  GM tube, a STC15W4K56S4 MCU, a LM1117-33 3.3 V regulator for the USB 5 V input, a APW7079 3.3 V booster for the 2xAA batteries, and five discrete transistors, seems to have provision to install an additional charger circuitry for NiMh batteries, despite the components were not installed and the circuit was basically bypassed, meaning that the USB port can not be used to the charge function. 
    • Based on the available videos and pictures, it seems that the firmware do not display the version during the boot procedure.
      • The trend graphic alarm threshold value is set at 0.5 µSv/h by default and can be changed to several higher values.  
  • A more recent PCB, available at least since 2022, featured here, based on a J321 GM tube, a STC8A8K64D4 MCU, a AMS1117-3.3V regulator for the USB port input, a APW7079 3.3V booster for the 2xAA batteries, and seven discrete transistors, do not have provision for a charger circuitry at all.
    • The firmware seems to be different from the older unit from 2019, and probably the features can be different too.
      • During the boot procedure, a welcome page identifies the Model as BR-6, and Version number as v3.0. 
      • The trend graphic alarm threshold value is not displayed, and the user guide do not mention such feature.
    • The current consumption from the 3 V dry batteries was:
      • Power ON and counting condition: 49 mA average
      • Power OFF condition: 000.0 µA (inferior to my meter resolution)
    • Conecting the USB port to a external 5 V DC source allows the unit to run without batteries. 
      • If batteries are installed and the USB port is used to operate the unit, switching from USB to batteries is seamless when removing the USB cable.

   

   

   

• Author
• Model page created by Jose Mesquita. See "Data change" for further contributors.

• Other Models

• Here you find 525 models, 503 with images and 29 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Unknown - CUSTOM BUILT: China