icom c4fm yaesu d-star

Icom radios do not use the C4FM digital mode
, which is a proprietary system from Yaesu. Icom's digital system is called D-STAR, and Icom radios are designed to be compatible with D-STAR, not C4FM.

C4FM is a Yaesu technology: C4FM is part of Yaesu's "System Fusion" digital communication system and is not a standard used by Icom.
Icom uses D-STAR: Icom radios are built for their own digital system, D-STAR, which is a different digital standard.
Compatibility: You cannot use an Icom radio to directly operate in C4FM mode. To use C4FM, you would need a Yaesu radio.
Analogue FM: While Icom radios don't do C4FM, they are fully compatible with standard analogue FM and can communicate with other analogue radios.
Specific Icom models: Models like the IC-9700 and ID-5100A are designed for D-STAR digital modes, notes Strictly Ham