Walkie-Talkie. #Altium #diyprojects #experiment #education #diy

Accelerate Your Career in Electronics Design Altium Student Lab: www.altium.com/in/yt/electricdhamaka #Altium #AltiumStudentLab This project demonstrates a low-power audio transmission and reception system operating in the shortwave / HF frequency range (around 12 MHz) for experimental and educational purposes. The system is designed to transmit voice or audio signals over a very short distance without any external amplification. Transmitter Section The transmitter is based on a single active device oscillator where audio from a microphone modulates the carrier frequency. Different frequency-determining components such as crystals (3 MHz, 12 MHz, 16 MHz, 27 MHz, 32 MHz) and an LC tank network are tested to study their effect on transmission frequency and stability. Key characteristics: Uses resistors around 10 kΩ and capacitors ranging from nanofarad to picofarad values Variable capacitor up to approximately 150 pF for fine tuning Inductance up to 350 µH for broadband or HF operation Operates from a battery supply Designed for very low output power and short range only No RF power amplifier or signal booster is used The transmitted signal is intentionally kept weak so that it remains confined to a small experimental area. Receiver Section The receiver uses a modified FM receiver module (CXA1691-based) adapted to detect non-broadcast HF / shortwave signals, including signals around 12 MHz. This allows direct reception of the locally generated signal without using any licensed broadcast band. Switching and Control A lever switch system is used to ensure that: Only one mode (Transmit or Receive) is active at a time Transmitter and receiver are never powered simultaneously Status Indication Three LEDs are used for clear visual indication: Red LED – Transmit mode active Green LED – Receive mode active Yellow LED – Power ON indicator This makes the system easy to operate and prevents accidental misuse. Purpose of the Project To study basic RF oscillation and audio modulation To experiment with crystal frequencies and LC tuning To understand shortwave signal behavior over short distances For educational learning and hobby experimentation only ⚠️ Important Warning & Legal Notice This project involves radio frequency transmission. Even low-power transmitters can fall under wireless communication regulations. Do NOT connect external antennas for long-range transmission Do NOT amplify or boost the RF signal Do NOT operate on licensed or commercial broadcast bands Use dummy loads or very short antennas only Operate strictly for testing, learning, and demonstration Radio transmission laws vary by country. The user is fully responsible for ensuring compliance with local wireless and spectrum regulations.