How to make the interoperability of walkie-talkies of different frequency ranges

In the actual use scenario, the communication interoperability between walkie-talkies of different frequency ranges often needs to solve the problems of frequency range, modulation mode, and protocol compatibility, etc. The following is a detailed introduction of several practical solutions. Here are some practical solutions for you. 

1. Confirm whether the walkie-talkie supports cross-band communication

Walkie-talkies in different frequency bands cannot realize intercommunication directly under normal circumstances. However, some walkie-talkie models support multi-frequency communication, the common one is dual-band UHF/VHF, the UHF frequency range is 400-470MHz, and the VHF frequency range is 136-174MHz, which usually can't realize the communication connection directly. BF-TD910 professional digital radio supports dual-band (UHF + VHF) communication, and the user can switch the frequency bands by manual operation.

Scenario: When both parties use walkie-talkies that support dual-band, you can manually adjust the two walkie-talkies to be set to the same frequency band to realize communication interoperability.

2. Use cross-band repeater

If the frequency bands of the two way radios are different, you can use the repeater to realize signal relay. A repeater can receive signals in one frequency band, e.g. VHF band, and forward them to another band, e.g. UHF band. When using a repeater, it is important to configure the input frequency (Rx) and output frequency (Tx) accurately, and to ensure that the CTCSS/DCS settings are consistent.

3. Replacement of equipment or use of adapters

If none of the above methods is feasible, the following two measures can be considered: firstly, replace the radios with equipment of the same frequency band, for example, use all UHF or VHF band radios; secondly, use cross-band bridging equipment, such as dual-band gateways.

4. Verify the modulation mode and CTCSS

Even if the radios have the same frequency, if the modulation mode (FM/NFM/WFM) or sub-tone setting is not the same, the interoperability cannot be realized. Therefore, you need to make sure that both walkie-talkies use the same modulation mode, and most common walkie-talkies use FM modulation. At the same time, double-check the CTCSS or DCS settings to ensure that they match.