How to set the DTMF to achieve the private call on RT87?

How to set the DTMF to achieve the private call on RT87?

Many customers talking about the DTMF, so what is the DTMF?

In short, DTMF is the Abbreviations of Dual-tone multi-frequency signaling, It is a channel with tone to represent the digital method, it can be used in analog voice channel transmission signaling, so in communication has a wide range of application.

If you want to more specifically,  it’s very complicated.Today we won’t talking more about it. Just Talking how to set DTMF on RT87 to achieve the private call.


First of all, we need two RT87 and one programming cable for RT87.


Program cable:


Now we connect RT87 with computer. Please choose the right port, the same as your computer.

The Port on software:

The port on your computer: please check “my computer- device manager”. Make sure they are consistent.

After Correct connection, Read from radio.


Now we Program RT87A radio.


RX Freq:435.25000, Tx Freq:435.25000. We will select channer16 to test.

Type: DTMF; ID 代码:892.

Step 2:

We click: Program -Optional Features-Optional Signal -DTMF

Fast Call List :8911, Group cade :A.

Step 3:

Set the Key Assigment: Choose Key function-1 is Optional Signal code as below:

Step 4:

Write to radio.


Then we set the other radio, Rt87 B. All program is the same as RT87 A, Except for the following:

Just programming the ID : 891, like below:

And the Program -Optional Features-Optional Signal -DTMF: Fast Call List : 8921.

Write to radio.


Now we will test them.

Turn On RT87 A and RT87B.

Choose the 16 channel, RX/TX:435.25000.

Press the side of the key 1, you can see “DTMF CALL?” On Screen,enter the DTMF Num such as “0”, press PTT, you can communicate between them.

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