FAQ for walkie talkie module SA818

By sdga:NiceRF Wireless Technology Co., Ltd

Today, the editor of NiceRF summarized some common problems of SA818 walkie talkie module, which is convenient for users to set up correctly and how to solve problems when they encounter problems. Next, the editor will give you a detailed introduction:


Our SA818 is a professional walkie talkie module with high integration and small size. It has a built-in high-speed microcontroller, high-performance RF transceiver chip and RF power amplifier, and provides a standard serial port for communication with the module, so that the relevant parameters of the module can be set quickly and easily And control the transceiver function.


Users only need to connect an audio amplifier, microphone, and speaker to this module to work as a small walkie-talkie. It uses 1ppm TCXO crystal oscillator, stable performance, simplified interface and ultra-small size make this module widely used, and it can also be easily and quickly embedded in various handheld devices to improve the overall performance of the terminal product.


SA818 is designed with optional high and low output power of 500mW-1W and high receiving sensitivity of -124dBm. It is widely used in small walkie-talkies, ignorant intercom systems, audio monitoring systems, outdoor sports products, etc.

SA818 walkie talkie module


The problems that users often encounter during use are transmission problems and reception problems. The transmission problem is low power and frequency deviation, and the reception problem is low receiving sensitivity. The following are the performance parameters of SA818 walkie-talkie for users' reference.

ParameterTest conditionMinTyp.MaxUnit
Power supply
Working Temperature range -302570
Current consumption
Sleep current  ≤1 uA
RX current  60 mA
TX current(High power)  650750mA
TX current(low power)  450550mA
Transmitting RF parameters
Frequency rangeUHF400 480MHZ
Frequency rangeVHF134 174MHZ
Out power(high power)@VCC=4.0V2829.531dBm
Out power(low power)2526.527dBm
Modulation frequency@1.5Khz/2.5KHZ frequency deviation 10 mV
Audio modulation distortion@1.5Khz/2.5KHZ frequency deviation 25%
SignaltoNoiseRatio@1.5Khz/2.5KHZ frequency deviation384045dB
adjacent-channel power@12.5K offset -60dBc dBm
CTCSS Modulation frequency 0.350.50.75KHZ
Receiving RF parameters
Receiving sensitivity13dB output voice signal to nat ratio -124 dBm
Receiving SNR@1.5KHZ  frequency deviation4550 dB
Audio output amplitude  700 mV
Audio Output impedance  200 OHm


Common problems and solutions:

 Why can't the normal communication between the modules?

1. The power connection is wrong and the module is not working normally.

2. Whether the module is in normal communication mode.

3. Check whether the frequency bands, channels and mute settings of each module are consistent.

4. Whether the module is damaged.

 Why is the transmission distance not far?

1. Excessive power ripple.

2. The antenna type is not matched or installed incorrectly.

3. Surrounding same frequency interference.

4. The surrounding environment is harsh and there are strong interference sources.

 Does it have RSSI function?

Our SA818 has RSSI function, and there are commands in the communication protocol to read RSSI.

 Serial command always returns ERROR:

There is no carriage return and line feed after the command.

 The serial port did not return:

PD pin (pin 6) is not connected to high level. PD must be connected to high level to work, if not connected to high level, the module is in a sleep state.

 Is the standard bandwidth 12.5K or 25K?

The standard bandwidth of our SA818 module is 12.5K.

 What is the speaker output power?

Our SA818 does not have an audio power amplifier. SA818 is an external power amplifier circuit, so your circuit will have as much power as it is.

 The module has no sound output:

1. Check whether the transmitting and receiving frequencies are the same and whether there is a Gaya tone. If they are not the same, the signal will not be received.

2. Press PTT to transmit whether there will be a large current, if so, the transmission is normal; whether the receiving AUDIO_ON pin will change from low to high, if it goes high, the frequency and sub-tone are correct; if there is no signal from AUDIO_ON, it is the transmitting frequency It is not the same as the receiving frequency, or the subtone is different.

3. If the above is normal and there is no sound, check whether the transmitting MIC circuit and the receiving power amplifier circuit are normal.

 Module crashes:

1. Check whether the power supply current of the module is more than 1A, if it is not enough, it may not be able to drive and cause the module to reset under low voltage.

2. Check whether it affects other equipment, which may interfere with the system's voltage regulator circuit or MCU work.

 After the module is used normally for a period of time, the communication distance becomes shorter and shorter:

Check to see if the emission current becomes smaller. If it becomes smaller than 300mA, the power amplifier IC may be burned out, and it must be returned to the factory for repair.


Our modules are equipped with a standard DEMO demo version for customers to debug programs, test functions and distances, etc. As shown below:

walkie talkie module SA818 DEMO 

For the specific operation method, please refer to the appendix "SA818 1W Embedded Small Volume Intercom Module V3.1.pdf" provided by our company.

The above is a summary and sharing of common problems and solutions for SA818 walkie-talkie modules. I hope to help you. If you don’t understand anything, please feel free to contact NiceRF at any time to provide you with the most sincere service.

Contact Us



Address: 309-314, 3/F, Bldg A, Hongdu business building, Zone 43, Baoan Dist, Shenzhen, China

Contact Us
Privacy Policy

Privacy Policy

· Privacy Policy

There is currently no content available



Address:309-314, 3/F, Bldg A, Hongdu business building, Zone 43, Baoan Dist, Shenzhen, China