• Country
• Great Britain (UK)

• Manufacturer / Brand
• DJS Electronics Ltd.; Weymouth

• Year
• 2010 ??

• Category
• Kit (Parts plus instruction) or building instructions only

• Radiomuseum.org ID
• 356372

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

• Main principle
• DSP, Digital Signal Processor

• Wave bands
• - without

• Power type and voltage
• Powered by external power supply or a main unit. / 7.5-15 Volt

• Loudspeaker
• - - No sound reproduction output.

• Material
• Various materials

• from Radiomuseum.org
• Model: CTCSS Tone Encoder CTCSS47 - DJS Electronics Ltd.; Weymouth

• Shape
• Chassis only or for «building in»

• Dimensions (WHD)
• 30 x 40 x 9.7 mm / 1.2 x 1.6 x 0.4 inch

• Notes

• The CTCSS47 tone encoder module uses a Microchip PIC16F627A 8-bit flash-based CMOS microcontroller with 128 bytes of EEPROM data memory. The microcontroller is programmed to generate 47 of the most commonly used CTCSS* tones from a 10 MHz crystal reference. The tone frequencies can be selected by switch, or by placing up to 5 jumpers in 6 positions. A subset of the 9 UK standard repeater tone frequencies (plus 100Hz, which is avoided in countries with 50Hz mains) are grouped together for convenient selection by a 4-pole switch. The accuracy of the tones is better than +/- 0.02%.

  A 78L05 regulator provides the 5 V required to power the module from supply voltages from 7.5 to 15 V DC via a series diode for reverse polarity protection. A Microchip MCP601 CMOS op amp provides a near sinewave output for the transmitter modulator, via a preset potentiometer that allows the amplitude to be adjusted up to a maximum of about 2 V p-p at the lower frequencies and 600 mV at the highest.

  The encoder was initially developed by CS Technology Ltd, and could be supplied in kit form or fully assembled by DJS Electronics Ltd, which purchased that company in 2013. Production ceased because of the limited availability of some parts, minimum order quantities, price increases, and finally the closure of DJS Electronics in 2024.

  *CTCSS (Continuous Tone-Coded Squelch System) is a type of in-band signaling used to prevent interference from other users on a shared two-way radio channel. By adding a low-frequency audio tone to the voice transmission, CTCSS circuitry mutes signals from users who are using a different CTCSS tone or no CTCSS at all. This helps to ensure clear and uninterrupted communication for specific groups of users on the same frequency.

• Net weight (2.2 lb = 1 kg)
• 0.020 kg / 0 lb 0.7 oz (0.044 lb)

• Mentioned in
• - - Manufacturers Literature (User manual)

• Author
• Model page created by Bruce Taylor. See "Data change" for further contributors.

• Other Models

• Here you find 1 models, 1 with images and 1 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from DJS Electronics Ltd.; Weymouth