500mW FM Stereo Transmitter | DIY FM Radio Station | 76-108MHz with Digital Display 2000m Range

The FM transmitter here is a compact and powerful device designed to broadcast audio signals as FM radio signals. With a total of 320 transmit frequencies, this device can easily be adjusted to your desired frequency with 1MHz or 0.1MHz steps. The LCD display shows the current transmit frequency for easy monitoring. The device has a maximum transmission distance of 2000 meters in the open air, thanks to its 500mW output power. The transmitter is powered by a 5V USB-type-C and has a power consumption of only 500mA.

The audio input signal is stereo and uses a standard 3.5mm audio interface. The transmitter’s antenna port is SMA. The audio SNR ratio is 63dB with a 0.05% THD. The device weighs only 120g and has dimensions of 80x48x10mm, excluding protruding parts.

Please note that the transmitter is not directly compatible with microphones, but can be used with a microphone amplifier. The volume of the audio input should be in an ‘appropriate’ level, as the ‘too loud input’ can cause distortion. This transmitter does not support microphone input. The transmission frequency and power can be easily adjusted using the two buttons on the panel. The device has a memory function, which saves the last frequency and power settings for the next time use.

Click to download Manual.

Specification:

1. Frequency Range: 76-108 MHz, adjustable with 1 MHz or 0.1 MHz step
2. Output Power: 500mW (0.01~0.5W) @ 88-108MHz
3. Receiving Equipment: Ordinary FM radio that is capable of receiving FM signals
4. Display: LCD display
5. Maximum TX Distance: 2000 meters in open air
6. Power Supply Voltage: 5V USB-type-C
7. Power Supply Current: 500mA
8. Input Signal: Stereo audio, 3.5mm port
9. Weight: 120g
10. Dimensions: 80 x 48 x 10 mm, excluding protruding parts
11. Antenna Port: SMA

Features:

• Adjustable frequency range: Operating range of 76-108 MHz with the option of adjusting the frequency in 1MHz or 0.1MHz steps, providing 320 total transmit frequencies.
• Memory function: The transmitter automatically remembers the last frequency setting and power level.
• LCD display: Displays the current transmit frequency, making it easy to monitor the frequency and power levels.
• Stereo audio input: 3.5mm audio interface.
• High output power: 500mW (0.01~0.5W) at a frequency of 76-108MHz.
• USB Type-C power supply: 5V DC with a power consumption of 500mA.
• Lightweight and compact: Weighs only 120 grams and has dimensions of 80x48x10mm excluding protruding parts.
• User-friendly design: The frequency and power can be adjusted with two buttons on the panel, making it easy to use.

Q: What is this for?
A: This is a FM transmitter. It can be considered as a small FM radio station. It inputs audio signals and outputs FM high-frequency signals, which are transmitted to the air through the antenna. People can receive the signal with a FM radio.
Q: Is this transmitter stereo?
A: Yes, this is a stereo transmitter.
Q: Can I use a microphone with the transmitter?
A: The transmitter cannot be directly plugged into a microphone. If a microphone amplifier is used, the amplified microphone signal can be input into the transmitter.
Q: How do I set the transmission frequency?
A: The transmission frequency can be adjusted with two buttons on the panel. You can select step changes, so the frequency changes by 1MHZ or 0.1MHz. Stop pressing the button for 5 seconds, and the transmitter will automatically remember the current frequency setting, and the next time you start it, it will automatically transmit at this frequency without having to set the frequency again.
Q: How do I adjust the transmission power?
A: By long pressing the UP button to enter the power setting mode, the transmission power can be set by pressing the DOWN/UP button. The transmission power can be set between 10mW and 500mW, with a total of 11 power levels. The button stops for 3 seconds and automatically switches to frequency adjustment mode, and saves the current transmission power. The next time you power on, it will automatically remember the last transmission power and frequency.

Q: Can it really transmit 2000 meters?
A: The transmission distance is directly related to the transmission power, transmission conditions, and antenna performance. The 2000-meter transmission distance is achieved under the conditions of 500mW transmission power, antenna installed on a higher place, and no obstruction between the transmission and reception. The antenna should be strictly tuned by a antenna analyzer, with the SWR of 1.2 or lower.
Q: Can I directly connect a telescopic antenna to the transmitter?
A: Yes.

Q: Why is it possible to receive signals even when the receiving frequency is +-0.1MHz nearby?
A: This is because the signal received by the radio is too strong, and this phenomenon will disappear if the radio is moved away from the transmitter.

Q: How is the transmitter powered?
A: The transmitter is powered by 5V DC with a USB Type C specification. The power consumption is approximately 500mA. If a poor quality power source is used, it may cause the transmitter to work abnormally or degrade the transmission quality, and the receiver may receive some obvious interference.

Q: What is the audio input interface of the transmitter?
A: The input uses a standard 3.5mm audio interface. The input volume should be appropriate. A friend in the evaluation area had input that was too loud and obviously distorted, so the volume had to be reduced to meet the quality of a typical FM radio station. Note: This transmitter does not support microphone input!