6. The antenna is mainly responsible for receiving radio waves from space. According to the selection rule of the antenna, the length of the antenna is as close as possible to the 1/4 wavelength of the receiving frequency. For example, to receive a 100MHz radio station, the ideal length of the antenna is L=(wave speed/frequency) /4=300000000/100000000=75cm. It is recommended to use a whip antenna dedicated to FM radio with a length of 75 cm.
Features:
Module function introduction
This module is equipped with a full-band short-wave FM radio module with Bluetooth audio receiving function and a receiving board SW Radio DSP. It also adopts the car-specific DSP radio chip. The FM sound quality is round and full, the bass is surging, the treble is clear, the layer is clear, and there is the feeling of CD sound quality. FM frequency band supports campus broadcasting 64-87MHz and civil aviation 118-135MHz. The full range of short wave supports 2.6-30MHz, the short wave of DSP is clear, and it is not easy to deflect the frequency and channel. The upgraded module has higher sensitivity and better anti-interference performance than the previous version. The receiver module integrates high-sensitivity radio chip DSP audio signal processing, professional Bluetooth 5.0 stereo audio receiver chip, stereo audio power amplifier, LED display and other functional circuits. It is a complete high-sensitivity full-band analog tuned radio module. Is a very suitable for DIY retro radio or Bluetooth speaker with full band radio function.|
Module electrical parameters:
Working voltage: 3.7 ~ 5.2V
FM frequency: 64-135MHZ (step 0.1MHz);
AM frequency: 504-1773KHZ (step 9kHz);
SW frequency: 2.3-30MHZ (step 5kHz)
This module has the following characteristics:
1. Use advanced digital audio signal processing technology (DSP) and phase-locked loop (PLL) demodulation technology to make the sound quality more realistic and the performance more stable.
2. With professional Bluetooth 5.0 stereo audio receiving function, it is convenient for mobile phones and computers to wirelessly connect to the module to play music through Bluetooth.
3. The sound quality is rich, the bass is full, the treble is transparent, and the good sound quality is unforgettable.
4. The display interface uses 4-digit LED digital tube display, which is intuitive and generous, making the display brighter and more thorough.
5. Three music playback modes: radio mode, Bluetooth mode, U disk music mode (the module has a USB interface reserved for U disk).
6. With the function of voice broadcast when switching the playback mode.
7.30 level digital volume adjustment range.
8. Equipped with stereo dual channel 3Wx2 audio power amplifier, only need to connect two speakers to form a high-end stereo radio.
Three key operation instructions
FM button:
1. In the radio mode, briefly press the FM key to switch the FM reception band (64-87MH, 87-108MHZ, 112-135MHz three bands cycle switching) function, long press the FM key> 2S to switch to Bluetooth mode .
2. In Bluetooth mode, briefly press the FM button for Bluetooth music pause and playback functions, long press the FM button> 2S to switch to other modes.
3. In the U disk music mode, briefly press the FM button for the U disk music pause and playback function, long press the FM button> 2S to switch to other modes.
AM button:
1. In the radio mode, briefly press the AM button to switch the reception mode to the medium wave reception function. Press the AM button for a long time> 2S to mute the function.
2. In the Bluetooth mode, briefly press the AM button to play the last song for the song cut function.
3. In the U disk music mode, briefly press the AM button to play the previous song function for the song cut.
SW button:
1. In the radio mode, briefly press the SW button to switch the receiving mode to the short-wave reception band (cyclic switching in 1-25 bands). Press the SW button for a long time> 2S to adjust the volume function.
2. In Bluetooth mode, briefly press the SW button to cut the song to play the next song function, long press the SW button> 2S to adjust the volume function.
3. In the U disk music mode, briefly press the SW button to cut the song to play the next song function, long press the SW button> 2S to adjust the volume function.
Note: Press and hold the SW button for a long time during the volume adjustment. When the volume is adjusted to the maximum volume of 30, the module will emit 5 beeps to serve as a reminder. When the prompt is over, the volume will return to level 0 and the volume will be increased again.
Precautions before use
1. When the module is connected to the antenna and the power supply, pay attention to check the voltage range of the power supply and the positive and negative of the electrode before powering on. The working voltage of this module is 3.7-5.2V, and the maximum voltage cannot be exceeded, otherwise the module will be burned. It is recommended that users use batteries or iron core transformers +7805 voltage regulator chips to supply power. Try not to use switching power supplies. Most of the EMI of switching power supplies will cause great interference in the AM/SW band, which may result in the failure to receive radios in radio mode. phenomenon.
2. If the user needs to expand the U disk to play music, the battery voltage must be stable at 5 ±0.2V, otherwise the module will not be able to read the U disk to play.
3. If users need an external audio power amplifier, it is best not to use Class D digital amplifiers, which will also interfere with the radio mode. Try to use a linear audio power amplifier.
4. The module defaults to radio FM (87-108MHz) receiving mode after power-on. You can search for radio stations by adjusting the TUNE potentiometer, and the frequency display value will follow the changes to show the current frequency. If the current FM channel is stereo, the "STERO" green indicator lights up. The module can be directly connected to two external 3W 4 ohm or 8 ohm speakers for listening (Note: try to use a large-capacity battery to supply power to the external speakers, so as to avoid unstable battery voltage due to excessive volume and sound playback effect).
5. The module AM antenna coil uses I-shaped 220uH inductance as the AM simple antenna (you can also receive a lot of units, you need to see if there is interference from the local signal. If the interference is large, you will not be able to receive the station). The user can replace it with Magnetic rod antenna (220-420uH). The magnetic rod antenna should be far away from the module as far as possible, so that the AM/SW band signal reception sensitivity is better and the reception is easier. Refer to the wiring diagram for details.
6. The antenna is mainly responsible for receiving radio waves from space. According to the selection rule of the antenna, the length of the antenna is as close as possible to the 1/4 wavelength of the receiving frequency. For example, to receive a 100MHz radio station, the ideal length of the antenna is L=(wave speed/frequency) /4=300000000/100000000=75cm. It is recommended to use a whip antenna dedicated to FM radio with a length of 75 cm.