How to make talkie-walkie RT21 New talk with Old ?

How to make talkie-walkie RT21 New talk with old ?

Many customers have the problem about how to make my new two way radio can talk with the old? Today we will use the RT21 As model, to study how to compilation with them.

Retevis RT21 is analog radio, if you want to make them can talk with each other, you just need to make sure the communication channels are with same frequencies and CTCSS/DCS.

1.What you need to make talkie-walkie RT21 New talk with old?

1.You need a C9018A programming cable for programming:

2.Download and install usb driver and software for RT21 by this link:

2.How to make talkie-walkie new RT21 talk with old RT21

A.Here’s a blog detail introduction about how to programme RT21:

Programming a frequency in new rt21 software:

Such as:

TX frequency: 465.23500

TX frequency: 465.23500


3.Progrmme old RT21 with same steps with NEW RT21


After NEW RT21 and old RT21 programme done, then try to talk each other, if they can TX/RX indicate it’s success to programme;


You can test your radio with the new RT21 In 1 channale, and the old RT21 in 13 channel, they can talk with each other.

If you have a lot of Rt21, just make them communication channels are with same frequencies and CTCSS/DCS.

Do you know how to make Retevis NEW RT21 walkie talkie  talk with old RT21? if you have anything questions, please contact us by email,, thanks


Retevis two way radio

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