Raytheon L750

The **Raytheon L750** is a classic, high-performance fishfinder and depth sounder that was a staple on many fishing vessels throughout the late 1990s and early 2000s. Known for its vertical "portrait" orientation and robust construction, it was designed to provide professional-grade sonar capabilities to serious offshore and coastal anglers. This unit is a dedicated sonar display, meaning its primary focus is on high-speed bottom tracking and clear target identification through its dual-frequency operation. Because these units are no longer in production, they are highly sought after as "head unit only" replacements for boaters who already have the specialized Raytheon transducers and power harnesses permanently installed in their hulls.
The display features a high-definition, FSTN grayscale LCD that provides excellent contrast, even in the bright, high-glare environments typical of an open cockpit. The **L750** operates on a dual-frequency system, typically utilizing **50 kHz** for deep-water tracking and a wider search area, and **200 kHz** for high-resolution detail and target separation in shallower water. With a powerful 600-watt RMS output, this unit is capable of reaching significant depths, often exceeding 1,000 feet depending on the transducer and water conditions. Its software includes advanced features such as A-Scope (real-time sonar), zoom modes, and a variety of alarms for fish presence and depth shifts.
For those looking to replace a damaged unit, it is important to note that the Raytheon L750 utilizes a specific **7-pin locking connector** for the transducer and a separate power/data cable. It is also compatible with SeaTalk networking, which allowed it to share data like water temperature and depth with other Raymarine or Raytheon instruments of that era. When sourcing a "head unit only," verifying that the pins are straight and the screen is free of "sun-burning" or delamination—common issues with older LCDs—is essential. The unit is housed in a rugged, waterproof casing that was built to withstand years of salt spray and heavy vibration.
As a legacy device, the L750 remains popular because of its simplicity and the high quality of its analog sonar signal, which many veteran anglers still prefer for reading bottom hardness and thermoclines. It mounts using a heavy-duty gimbal bracket that allows for easy tilting or quick removal at the end of the day. While it lacks the modern color screens and CHIRP technology of today's units, its reliability and "workhorse" reputation make it a valuable find for maintaining a classic electronics suite without the need for a complete and expensive hull re-rigging.