BH438A Wireless FM Transmitter
WIRELESS FM TRANSMITERUSER MANUAL
PRODUCT STRUCTURE
- Knob Button: Rotate clockwise to increase frequency (in FM mode) or volume. Rotate anticlockwise to decrease frequency (in FM mode) or volume
- Multifunctional Button: Play/Pause, Answer/Hang Up/Decline/Redial Last Number, Long press CH for 2s to enter FM tuning mode
- TF Card Slot (Max. 64G)
- U Disk Port (Max. 64G)/5V-1A Charging Port
- PD3.0 Type-C Charging Port (Max.18W)
- QC3.0 Quick Charge Port (5V/3A, 9V/2A, 12V/1.5A)
- Microphone
- Deep Bass Sound Effect Button
- Digital Display
- RGB Light
- Short Press: Next Track. Long Press for 2s: Enter modes switching mode (Bluetooth/U Disk/TF Card)
- Short Press: Previous Track. Long Press for 2s: Enter/Exit from Siri
- Light Effect Controlling Button: Short press continuously to switch 9 different lighting colors
SPECIFICATIONS
| Product Name | Bluetooth FM Transmitter |
| Effective Distance | 5m |
| FM Frequency Tuning Range | 88.1-107.9MHz |
| Support Audio Format | MP3/WMA/WAV/FLAC |
| Support Bluetooth Protocol | A2DP, AVRCP, HFP, HSP |
| QC3.0 Quick Charge Port | Support QC3.0 Quick Charge (5V/3A, 9V/2A, 12V/1.5A) |
| PD3.0 Type-C Quick Charge Port | Support PD3.0 Quick Charge (Max.18 W) |
Power On/Off
Power On
- Start your car and plug BH438 in its cigarette lighter, and the product will turn on after it’s energized.
- If the product is plugged in the cigarette lighter but it’s in a power-off state, you can short press any button on it to turn it on.
Power off
- It will turn off once you cut off its power supply.
- When it’s in power-on state, long press its light button
for 3s to turn it off.
Note: When the product is turned on or off via its buttons, its charging ports still work for charging.
Ring RGB Light Adjustment
In the power-on state, short press light button 
to switch 9 modes among static RGB, dynamic RGB, red, green, blue, orange, purple, cyan, and white. When you use the product again, it will display the lighting mode that you set last time.
Turn On/Off the Ring RGB Light
- Turn On: When you use the product for the first time, the light displays static RGB by default. When the light is in a power-off state, short press the light button ® to turn it on.
- Power Off: When the light is turned on, short press the light button successively until the light goes out.
FM Frequency Tuning and Bluetooth Pairing
Attention: When using a product for the first time, you need to adjust its FM frequency to a blank FM frequency (An unoccupied frequency/A frequency without any broadcast/ A frequency only with noise) and make its blank FM frequency to be the same as that of your car. To ensure the best experience of tone quality when every time you use the product, please make sure the blank frequencies (An unoccupied frequency/A frequency without any broadcast) between BH438 and your car are the same.
- Adjust your car’s FM frequency to a blank frequency (An unoccupied frequency/A frequency without any broadcast/A frequency only with noise), such as FM88.8.
- Long press the CH button for 2s to enter FM tuning mode, and the LED display with frequency will flash. Rotate the knob button to adjust its frequency. Rotate clockwise to increase the frequency and anticlockwise to decrease it.Meanwhile, there are 2 methods to adjust a product’s blank FM frequency to be the same as that of your car such as FM 88.8.Method 1: Quick Tuning – Long press button to increase the frequency and to decrease it.Method 2: Precise Tuning – Short press button to increase frequency and button to decrease it.
- Bluetooth Connection: Turn on Bluetooth on your smart devices. Search “BH438” and connect it, and you can use the product after the successful connection. (When used again, BH438 will reconnect the last device connected before.)
- Please appropriately turn up the volume of \mitt- phone.
Bluetooth Hands-free Function
A. Answer a Phone Call: Short-press 
buttons.B. Hang Up the Phone: Short press button.C. Reject a Phone Call: Long press for 2s.D. Redial the Last Number: Double press button.
Music Function (Please use this function after the FM frequency tuning is successfully completed)
3 Music Sources – Bluetooth/U Disk/TF Card
A. Bluetooth Mode: After your smart device (eg. Phone) is connected to the product’s Bluetooth successfully, the music on your phone will be synchronized to your car speaker if you play music on your phone.
B. TF Card/U Disk Mode: Plug TF Card or U Disk in product’s port, and it will automatically recognize and play the music in your device.Note: To avoid affecting user experience, please use only one music source when every time you use the product.
Music Source Selection
A. Bluetooth/U Disk/TF Card Switch: Long press PH for 2s to switch music modes among Bluetooth, U Disk or TF Card.B. AutoPlay in TF Card/U Disk Mode: Plug and Play (Only support music mode of repeating playlist. Not support music mode like repeating one song and shuffle).C. Power Cut Memory: When you reboot the product, in U Disk/TF Card mode, it will enter the previous playing mode and will automatically replay the song before the power cut. In Bluetooth mode, you need to manually enter music software to play music.
Music Playing Operation
A. Play/Pause: Short press button.B. Previous Track or Next Track: Short press 
or 
button.C. Volume Up: Rotate knob button clockwise.D. Volume Down: Rotate knob button anticlockwise.
Voice Assistant
Manually Operate BH438 to Use It
A. Long press button for 2s to enter voice assistant.B. Long press button for 2s to exit from the voice assistant.Friendly Tips: For Android devices, when you’re going to use your voice to directly wake up the voice assistant, please turn up your phone’s and BH438’s volume to their maximum volume level first, and adjust the car speaker’s volume according to your needs.For iPhone, the instructions of the “Hey Siri” function can refer to the following:A. Turn on Siri settings on your phone. r–
B. Complete the voice recognition according to Sin instructions.C. Use the Siri function directly on your phone.
Note: This function is not available for some phone brands. (Supported Phone Brands are iPhone, Samsung Phones and Original Android Phones)
QC3.0 Instructions
- For smart devices that support quick charge, the maximum voltage and current in QC3.0 charging are 5V/3A, 9V/2A, 12V/1.5A.
- For smart devices that do not support quick charge, the charging output by default is 5V/2.4A.
PD3.0 Instructions
- For smart devices that support quick charge, the maximum voltage and current in PD3.0 charging are 5V/3A, 9V/2A,12V/1.5A.
- The maximum power can reach up to 18W.
Note
- Do not turn up your radio’s volume too loud in case of increasing its background noise.
- Although the transmitting power of our FM transmitter is strong, for ensuring the best sound effect, please try to avoid adjusting to the frequency of the local radio station with a strong signal.
- Do not use the product in too hot/cold, dusty or damp environment.
- Do not break or throw the product to prevent surface or unit damage.
- Do not disassemble the product personally. Please contact the seller if you have any questions or problems.
NOTE: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:
- Reorient or relocate the receiving antenna.
- Increase the separation between the equipment and
- Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
- Consult the dealer or an experienced radio/TV technician for help
report this adChanges or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment.This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:
- this device may not cause harmful interference, and
- this device must accept any interference received, including interference that may cause undesired operation.
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