SI-TEX SP-120 Color System w/RFB & Remote Mechanical Drive 1983-93 Mercury I/O, Volvo Diesel

The SI-TEX SP-120 Color System with RFB and Remote Mechanical Drive is a dedicated sounder and chart recorder built for the serious angler and boater navigating 1983–1993 Mercury I/O and Volvo Diesel-powered vessels. This system represents proven marine electronics from an era when durability and reliability were non-negotiable—equipment that needed to perform in saltwater and freshwater conditions alike. Whether you're fishing deep structure, mapping bottom transitions, or recording waypoints during extended offshore trips, the SP-120 delivers the fish-finding capability and data logging that built SI-TEX's reputation among commercial and sport fishermen.

The SP-120 combines a color LCD display with remote mechanical drive functionality, allowing operator control from helm or flying bridge without running additional cables through the cabin. The RFB (Remote Fish Finder Box) integration means your sounder operates independently while chart and log data remain centralized—a practical design that minimizes installation complexity on older powerplants. The mechanical drive system is engineered for the electrical and fuel delivery characteristics of Mercury and Volvo Diesel engines from that production era, ensuring stable gauge operation and accurate depth readings even under heavy load or adverse weather conditions. The color display cuts through glare and delivers superior target separation, making it easier to distinguish bottom hardness, fish schools, and thermoclines at a glance.

Owners of classic or vintage Mercury and Volvo-powered inboards and outboards will find the SI-TEX SP-120 a direct replacement or upgrade path for aging navigation and sounder systems. Installation requires mechanical and electrical compatibility with 1980s–1990s I/O engine management, making professional marine installation advisable. The system is ideal for anglers who log fishing data, boaters restoring vintage vessels to original-era electronics, and operators seeking proven, non-GPS-dependent sounder technology for backup or redundant fish-finding. Weighing just 1 pound, the main head unit integrates cleanly into existing dash or console space. This is genuine fishfinder heritage—equipment trusted by generations of serious water users.