Adjustable FM Transmitter Module

This FM transmitter module is engineered for seamless integration into compact custom electronics. It delivers stable RF output across the 88–115 MHz band, most commonly centred at 99–101 MHz out of the box. Physical dimensions are approx. 25 × 18 × 8 mm; weight is under 3 g. Power input is flexible: DC 2V–9V, with typical current draw of ~9mA at 3V. Output impedance is fixed at 50 ohms. Users must solder power leads and attach an external antenna—no onboard connector or battery holder is included. Its architecture integrates a high-stability local oscillator, signal isolation amplification, LC-based filtering, and impedance matching networks to maintain spectral purity and minimise harmonic emissions. Tested range: up to 100 m in open space, 10–30 m indoors (3V supply). Intended applications include wireless microphone monitoring, discreet audio recording, remote surveillance audio links, and personal assistance systems. Not recommended for loud live sound environments due to inherent sensitivity. Compatible with all standard FM receivers covering 88–108 MHz. Package contains one bare PCB module only—no enclosure, cables, or accessories.