Humminbird AS GPS HS NMEA 2000 GPS Antenna with Heading Sensor

The Humminbird AS GPS HS (part 730029-1) is the external GPS antenna with built-in heading sensor for Humminbird fish finders and chartplotters that need rock-solid GPS plus true boat heading delivered over a NMEA 2000 connection. The 2.5-meter accuracy GPS receiver with dual-band reception and WAAS / EGNOS augmentation handles position. the internal flux-gate compass handles heading. the NMEA 2000 interface delivers both data streams to the chartplotter (and to any other NMEA 2000 device on the boat) via plug-and-play connection. The right antenna upgrade for boats running 360 Imaging, MEGA Live, or any other sonar feature where the chartplotter needs to know where the boat's bow is pointing to draw the sonar return correctly on the chart.

Why a heading sensor matters for modern sonar. Older Humminbird sonar features (2D, DI, SI) work fine with just a GPS antenna because they only need to know where the boat is, not which way it's pointed. Newer features (360 Imaging, MEGA Live forward-imaging, structure scanning with proper screen orientation, side-imaging waypoints with accurate offset placement) require the chartplotter to know the boat's heading so the sonar return shows up in the correct direction on the screen. Without a heading sensor, the chartplotter has to estimate boat heading from successive GPS positions, which only works while the boat is moving forward. At Spot-Lock, at trolling-motor anchor, or at idle, GPS-derived heading is meaningless. The internal compass on the AS GPS HS solves that: heading is accurate at zero speed, at slow troll, and at WOT.

2.5-meter GPS accuracy with dual-band reception. The GPS receiver inside the AS GPS HS uses dual-band GPS (L1 plus a second band) with WAAS / EGNOS satellite-based augmentation. The dual-band reception filters out atmospheric position error that single-band GPS can't correct, dropping typical position uncertainty to about 2.5 meters in clear-sky conditions. For waypoint placement, that's tight enough to drop a waypoint on the bow of a fishing boat and come back to it later within the boat's own length. WAAS coverage handles North American operation. EGNOS handles European operation. the antenna works in either region.

NMEA 2000 connectivity. The included 20-foot cable terminates in a NMEA 2000 Micro-C connector for plug-and-play integration with the boat's NMEA 2000 backbone. Drop the antenna's tee into the backbone, the antenna sends its GPS and heading data onto the network, and any compatible chartplotter, fish finder, or autopilot on the network reads it. For boats without a NMEA 2000 backbone, the antenna can also connect directly to a single Humminbird chartplotter via the supplied direct cable. Either configuration is plug-and-play.

20-foot cable for flexible mounting. The 20-foot integrated cable lets you mount the antenna at the bow, at the t-top, on the leaning post, on the swim platform, or anywhere else with clear sky exposure, and still reach the chartplotter at the helm. Most center console installs put the antenna on the t-top forward edge for clear sky and minimum metal-mass interference with GPS signal reception.

1-inch threaded stem mount with hardware. The base of the antenna unscrews to expose a 1-inch standard threaded stem so the antenna can be screwed onto any standard 1-inch threaded antenna mount (the same thread used for VHF antenna mounts on most boats). For flat-deck mounting, the included mounting hardware kit lets you bolt the antenna directly to a flat surface. Either install path takes about 10 minutes.

Plug-and-play with Humminbird. For Humminbird HELIX, SOLIX, APEX, and XPLORE-series chartplotters, the AS GPS HS connects to the unit's Ethernet / NMEA 2000 port and the chartplotter automatically detects the new GPS source and the new heading source. No menu configuration, no source selection, no calibration steps required to get the antenna online. The internal compass does require a one-time auto-calibration spin (drive the boat in a slow circle a few times) to align the compass to the boat's local magnetic field. After that, the heading reading is accurate and stable for the life of the antenna.

Internal compass calibration. The flux-gate compass inside the antenna self-calibrates the first time it sees the boat go through a full slow circle (typically two or three full circles at trolling speed). The chartplotter shows a calibration progress indicator so you know when the compass is fully aligned. Once calibrated, the heading reading stays accurate as long as the antenna stays in the same physical location on the boat and the local magnetic environment doesn't change drastically (no new metal added near the antenna). If you ever move the antenna or change the boat's magnetic signature significantly, just run another calibration spin and the compass realigns.

Mounting location matters. The internal compass is sensitive to nearby ferrous metal and to current-carrying wires that produce magnetic fields. Best practice: mount the antenna at least 18 inches away from any motor, alternator, large speaker magnet, or high-current cable. T-top mount is ideal because it's high above the metal mass of the engine and any other big metal items on the boat. Direct deck mount is fine on a fiberglass boat with no nearby metal. Avoid mounting the antenna directly on top of an aluminum t-top frame or near a high-current battery cable run.

Saltwater rated and tough. The plastic housing is UV-resistant and saltwater-rated. The cable is over-molded onto the housing for a watertight seal at the cable entry. The antenna survives spray, rain, direct sun, and the temperature swings of the marine environment without service for years. The dome shape sheds water cleanly so no standing water sits on the antenna in rain or rough water spray.

What's in the box. One AS GPS HS antenna with the over-molded 20-foot integrated cable, NMEA 2000 Micro-C terminator, the direct-connect cable for single-device hookup, the 1-inch threaded stem adapter, the flat-mount hardware kit, and the install instruction sheet.

Compatibility note. The AS GPS HS works with all current and recent Humminbird chartplotters that support external GPS / heading source via NMEA 2000 (HELIX 5 series and newer, SOLIX, APEX, XPLORE). For older Humminbird units (pre-HELIX) that don't have NMEA 2000, the AS GPS HS isn't the right antenna. those use the older puck-style GPS antenna instead.

2-year limited Humminbird warranty. Same-day shipping before 3 PM ET on in-stock units.