The communicate distance would be disturbed by the following factors:
(1) Environment: If you use it around high buildings and large mansions, the communication range is smaller.
(2) Weather: If you use the radio in rainy day, the radio performance may be poor.
(3) Power: If the power of the radio is very low, you will have a poor communicate distance.
This happens because the radio is wrongly programmed. This noise is an indication that the channel frequency programmed is out of the frequency range supported by this radio. Please check your setting or turn to a professional engineer for help.
Usually, when the radios are at the edge of the coverage area or in some places where the radio signals are interrupted or blocked, this symptom will happen. Please kindly verify the above. If necessary, please return the radio to Kaili authorized dealer for maintenance.
First, please verify that the channel frequency and the CTCSS you are using are the same as those of your group members. If the channel frequency and the CTCSS are the same, please verify that your group members are within the radio coverage.
Please change your CTCSS for the channel. At the same time, you also need to the CTCSS for all the radios in your group. If you don't like this, you may apply another channel frequency.
Firstly, set the two radios in the same frequency, secondly, set the same CDCSS/CTCSS, and then they can talk with each other.