... , 136-174MHz , Channel spacing: 12.5Khz,25Khz optional Embedded Data modem The FC-301/D Series of RF Link Modules ... coupling, walkie-talkie etc. When attached Modem, 301D can transmit data directly. 2400bps Modem board is an optional accessory, if the ... data transmission is required in the application. ApplicationsIndustrial telemetry & wireless ...