1. Use STC8H1K17 microcontroller as the main control, built-in PLL local oscillator, and built-in frequency indication circuit (using a seven-segment LED digital tube, the display unit is 1KHz, the photo has color difference, the actual color is red), the working frequency covers 28.400-29.300MHz, supports AM mode.
2. The reception uses a primary frequency conversion circuit, with TA2003 doing the receiving mixing, mid-amplification, and AM detection. The output audio signal is adjusted by a digital potentiometer to adjust the sound volume, and then sent to the LM386 for amplification.
3. The transmission adopts Class E amplification, with an average power of 5W.
4. Relay switching is used for sending and receiving, and the machine is equipped with a hand microphone.
5. Our store's original code, on-board digitally controlled volume potentiometer, supports automatic saving of configuration, supports intermediate frequency calibration, and supports crystal oscillator frequency calibration.
6. 12V power supply, PCB board size is 71*100mm, which can be easily placed into a 76*35*100mm aluminum chassis for use.
7. This kit comes with a hand microphone.
main indicators
Power supply: 12V
Operating current: receiving ≈ 130mA @ 12V; transmitting ≈ 1300mA @ 12V
Frequency range: 28.400-29.300MHz, 10KHz/1KHz step
Working mode: AM sending and receiving