Working voltage: 2V-5V (mobile power can be used, but with regulated power supply, mobile phone charger may have AC noise, if the voltage is too high, it will burn the launch tube)
Working current: 30-80mA (measured input working current: 4.8V-87mA, 3.6V-63mA, 2.4V-36mA, test 80cm wire for the antenna, respectively, using four, three, two BPI2100mah nickel-metal hydride rechargeable battery test)
Transmitting frequency: 80-110MHz (complete coverage of home FM radio frequency)
Transmitting power: 150mw (C models), 50 meters - 800 meters (depending on the antenna efficiency determines the distance)
Receiving method: ordinary household FM radio receiving. The FM radio that comes with the phone can also be received, but the Internet app that the software APP requires network traffic cannot be used.
Emission distance: The linear transmission distance of the obstacles can reach 800 meters or more (6V power supply, 80cm professional antenna, Desheng PL606 high sensitivity radio test results, if the common antenna or the obstacle group environment test in the building group, the distance will be shortened)
On-board microphone with external audio input (mono)
Input microphone and audio sensitivity are adjustable, and the transmission frequency is continuously adjustable
Transmit power: 5v input up to 150mw transmit power, more than 300m
All imported components, stable operation, frequency does not drift, hand touch antenna does not drift
Broadband modulation, superb sound quality, comparable to FM radio station sound quality
If the module is hot, it means that the antenna is not very well matched. Some of the transmitted power cannot be transmitted through the antenna. It becomes heat and will make the board hot. When this situation is found, it is necessary to consider adjusting the antenna.
(1) The antenna determines the transmission distance. A good antenna can transmit hundreds of times more than a few times more than a poor antenna.
(2) It is recommended to use 75-80 cm long, 0.5-1 mm diameter enameled wire, directly soldered to the transmitting antenna pad on the circuit board, straightened and used vertically, the effect is better.
(3) If the distance requirement is not high, but you want to be more subtle, you can use ordinary wires, which is shorter, but it will reduce the launch distance. Please test it yourself.
Many customers ask this question, you can calculate it yourself, the battery is different, the capacity is different, and the module works different time.
Calculated as follows:
5v power supply - use time (hours) = battery capacity (mah) divided by 85ma
3.7v power supply - usage time (hours) = battery capacity (mah) divided by 63ma
How long does a Samsung 2600mah 18650 lithium battery (3.7V) give power to this module?
2600mah divided by 63ma = 41.2 hours, probably can be used for 41 hours, it is very power-saving.
Frequency Debugging Instructions
In the first step, after the module is powered up, touch the rightmost triode to see if it has temperature (the fourth from the left, the volume is slightly larger). If it is warm, it means that it has started working. If there is no heat, the power supply is not connected. You can use a multimeter to measure the positive and negative voltages of the module. (100M power is low, the triode is not hot, you can jump directly to the next step)
The second step, after the first step is completed, ensure that the module is powered on normally, turn on the FM radio, turn to the maximum volume, adjust the frequency with the manual mode of the radio, search for 88-108mhz completely, and you should be able to find the frequency (the default factory default frequency is 96- Between 101mhz). Do not use automatic search. Automatic search sometimes skips the frequency of the module and does not stop automatically.
In the third step, the above steps still can't find the frequency. Don't worry, you can fix the radio to a frequency without a radio station, such as 100mhz. Then use a 0.8mm extra-small non-inductive screwdriver to tighten the frequency-adjusting trimmer capacitor. It must be rotated very slowly. When the radio suddenly has a sound, stop it. Then use the radio to manually adjust the frequency. It should be near the fixed frequency. Find a frequency, the sound is the most clear and clear, debugging is completed.
1 x 80-110MHz FM Transmitter Wireless Microphone Surveillance Spy Bug Board Module
Instructions are NOT included. We don't provide technical assistance please make sure that you are familiar with the product before purchasing.