Raymarine Quantum 2 Q24D Doppler Radar with 15M Cables

The Raymarine Quantum 2 Q24D Doppler Radar is the second-generation Quantum solid-state radar with Doppler collision avoidance - the radar that classifies moving targets as inbound (red) or outbound (green) automatically using Doppler frequency-shift processing on every return. This particular configuration (T70417) ships with the long-cable kit: a 15-meter (49 foot) power cable and a 15-meter data cable, sized for installations where the radar mounts on a mast, arch, hardtop, or radar tower with a long cable run back to the helm-mounted MFD.

Why Doppler matters for collision avoidance. Conventional radars show every return as the same color - one indistinguishable green or yellow blob on the screen. You see returns but you don't immediately know whether each return is a stationary buoy, an anchored sailboat, or a tanker bearing down on you at 18 knots. Doppler radar measures the frequency shift on each return (returns from inbound targets arrive at slightly higher frequency, returns from outbound targets at slightly lower frequency - the same effect that makes an ambulance siren sound higher in pitch as it approaches and lower as it passes). The Quantum 2 processes that frequency shift on every pulse and color-codes the target on the display: red for inbound (potential collision risk), green for outbound (moving away, not a threat), and neutral colors for stationary targets. In a busy harbor, that color coding instantly highlights the boats that are headed your way out of dozens of returns - a game-changer for night and reduced-visibility piloting.

What CHIRP pulse compression adds. The Quantum series uses solid-state CHIRP (Compressed High-Intensity Radar Pulse) technology rather than the old magnetron-based pulse generation. CHIRP delivers three real advantages: (1) Minimum detection range drops to 18 feet - magnetron radars typically have a 25-50 foot blind zone right around the boat because they can't separate transmit and receive that close. The Quantum 2 sees the buoy 18 feet off the bow when you're feeling your way through fog into an unfamiliar harbor. (2) Target separation improves dramatically - individual boats in a crowded mooring field show as separate returns instead of merging into one blob. (3) Long-range detection at low power - the Quantum 2 runs 17-20 watts peak and still reaches 24 nautical miles, vs the 4 kW peak power of comparable magnetron radars (which is why the Quantum is safe to mount near living quarters and at head-height on small boats).

Safety Sector - the under-appreciated feature. Doppler is great at flagging moving threats, but stationary hazards in your path are equally dangerous - the anchored sailboat or unlit buoy directly ahead is just as bad as an incoming vessel. The Quantum 2's Safety Sector feature processes a 15-degree forward arc out to approximately 200 meters and treats stationary targets in that arc as inbound red threats. Result: the rock pile dead ahead lights up red even though it isn't moving, drawing your eye to the immediate danger. The Safety Sector arc itself isn't visible on the display - only the highlighted targets are - so the radar screen stays clean.

MARPA target tracking. Mini-ARPA (Automatic Radar Plotting Aid) target tracking is built into the Quantum 2 - up to 10 simultaneous tracked targets with automatic acquisition (Doppler-enabled MARPA doesn't need you to set guard zones manually - the Doppler processing identifies moving targets automatically and starts tracking them). For each tracked target, the radar continuously calculates true course, true speed, CPA (closest point of approach), and TCPA (time to closest point of approach). Audible alarms fire when a target crosses your CPA threshold. This is the same MARPA technology used in commercial collision-avoidance systems.

TrueTrails target history. Every moving target on the screen leaves an adjustable trail showing its past position. Trail length is user-configurable from a few seconds to 10+ minutes. Practical use: in a busy crossing situation, the trails make it instantly obvious which vessel is turning, which is holding course, and which has been weaving - so you can predict where each target is going next and make smart maneuvering decisions.

Physical specs and mounting. The Quantum 2 Q24D is the 18 inch dome (radome) configuration - 21.3 inches outside diameter, 8.25 inches tall. White marine-grade ABS housing, IPX6 waterproof rated for direct heavy spray and brief immersion. Mounting bolt pattern matches the previous-generation Raymarine 18-inch radomes (Quantum 1, Digital 18" HD Color, Pathfinder 18"), so this is a drop-in replacement for boats already running an older Raymarine 18-inch dome on an existing mast bracket, arch mount, or pole mount. Weighs about 50% less than equivalent magnetron radars, which matters for sailboats running mast-mounted radar where weight aloft affects performance.

Power and electrical specs. 12 to 24 VDC input (handles either electrical system without configuration). Peak transmit power 17-20 watts, standby around 7 watts. Total power draw is a small fraction of conventional magnetron radars - matters significantly on sailboats and small powerboats running off house battery for extended periods. The radar wakes from standby in seconds (no warm-up time, unlike magnetron radars that take 60-90 seconds).

Network connectivity. Two connection options: (1) Wired through the 15-meter data cable to a Raymarine RayNet connection on the MFD or RayNet network switch, plus 12-24 VDC power through the 15-meter power cable. (2) Wireless via the built-in Wi-Fi to compatible Raymarine MFDs (Axiom and Axiom Pro series). The wired connection is more reliable for sustained heavy use and is the standard install on commercial and larger recreational vessels. Wi-Fi is convenient for small-boat installs where running a data cable through the boat is impractical - but Wi-Fi range is line-of-sight limited and works best at distances under 50 feet between radar and MFD.

MFD compatibility. The Quantum 2 is a Raymarine-network device that connects to Raymarine Axiom and Axiom Pro multifunction displays (current generation) and the older eS Series, gS Series, and a-Series displays (last two generations). It does NOT connect to other-brand multifunction displays - if your boat runs a different brand of MFD, you need to use that brand's matching radar. For Raymarine MFD owners, the Quantum 2 is the current premium dome radar option in the Raymarine catalog.

Why the 15-meter cable kit. The standard Quantum cable kit comes with 10-meter cables, which is enough for most center console and small sportfisher installs where the radar mounts on a hardtop or small radar arch within 30 feet of the helm. The 15-meter (49 foot) kit (this product) is sized for sailboats with mast-mounted radars (typical mast height to helm cable run is 35-45 feet on a 35-40 ft sailboat) and larger powerboats with tower-mounted radars where the run from radar to helm exceeds 30 feet. Order the kit that matches your install - longer cables can't be field-spliced cleanly, and shorter cables strand the radar.

What's in the box. One Quantum 2 Q24D 18-inch radome, mounting hardware, one 15-meter power cable, one 15-meter data cable, basic installation documentation. Mounting bracket (mast bracket, pole mount, arch mount) is sold separately and selected based on installation location. RayNet network connections may require additional adapter cables depending on existing network topology.