Dual-input Low Power FM Transmitter for Drive-in Audio

This low-power FM transmitter is designed for professional short-range broadcasting, ideal for drive-in cinemas and other temporary audio delivery setups. Operating within the FM band (87–108 MHz), it enables clear wireless transmission directly to standard FM radios in vehicles or portable receivers.

The transmitter features two separate audio inputs: one for line-level sources such as laptops, media players, or phones, and a second input that supports direct microphone connection—useful for live announcements or commentary. Audio input is via stereo 1/4" (3.5mm) jack, with independent level adjustment and over-modulation indicators for signal clarity. The unit delivers Hi-Fi stereo sound with reliable phase-locked loop (PLL) frequency control, selectable via LCD interface.

Key Specifications:

• Frequency range: 87–108 MHz
• Output power: up to 0.5 W
• Frequency stepping: 100 kHz
• Coverage: approx. 200 metres (portable radios), up to 750 metres (car radios)
• Dual inputs: Line-level (e.g. laptop/phone) and direct microphone
• Audio distortion: 0.30%
• Audio input: Stereo 1/4" (3.5mm)
• Power requirement: 12V DC, <3A
• Frequency response: 50 Hz – 15 kHz
• Operating temperature: –10°C to 45°C
• Dimensions: 190 × 125 × 45 mm
• Compliance: FCC Part 15, Industry Canada standards

Additional protections include temperature and standing wave safeguards. Compatible with telescopic or GP-style antennas, the unit is suited to both indoor and outdoor use where short-range FM audio is required.