The JTMIC1 microphone is shipped with Jetstream JT220M radio. It has a 16 key pad for generating all 16 DTMF tones, allows control of some functions of the radios, and enables direct frequency entry or memory selection.
Theory Of Operation
From an appearance and functional perspective, this appears to look and work identically to the Alinco EMS-57 microphone. Internally, the schematic is different. The JTMIC1 uses a an Elan RM78P565AFM processor. This has an integrated DTMF generator, whereas the EMS-57 uses a M37531 4-bit processor with an external Toshiba TC35219F DTMF generator.
For the protocol that the microphone uses to communication to the radio, please see the Alinco EMS-57 microphone.
Documents, Schematics, Etc
- EM78P565 Datasheet (305 KB)