Diagnose RADAR (task)

Task: diagnose and if necessary, repair Nevermore's RADAR system.

Fall 2007 Status

Nevermore was delivered with the following installed systems:

• Raytheon R20XX Display unit mounted above the nav station
• Raytheon R20XX raydome antenna mounted on the mast
• Raytheon Raychart 600XX chart reader
• Raytheon GPS receiver
• Fluxgate compass
• Four electronic chart cartridges for areas in Long Island Sound

None of these systems were tested or even powered on until May 2008.

Antenna and Display Diagnosis

The RADAR antenna and display seem to work. Both of these units seem in good condition, as does the interconnecting cable. They will be reinstalled before Nevermore is put back in the water.

Chart Reader Diagnosis

This unit and the cable that connects it to the display are both in good condition. It displays electronic charts on the radar screen and connects to a GPS receiver to show the ship's position on a chart on the Radar display. That may sound nifty, but keep in mind:

1. The screen resolution is very low and monochromatic (black and green),
2. The chart resolution is very low (about 1/2 mile),
3. It uses 1992 technology, so it takes about 30 seconds to update the chart image on the screen whenever you try to pan,
4. It only has chart cards for Long Island Sound and they don't make cards for this reader anymore,
5. It doesn't superimpose the chart on the radar image (which would be useful), it puts the radar image in a little box on the side of the chart image.
6. And it's all pretty obsolete with respect to our current GPS unit.

Re-installation of the chart reader is NOT recommended.

GPS Receiver

The GPS receiver is light-bulb shaped, about 4" in diameter, about 6" high and was previously mounted on the stern rail.

The cable that connects it to the chart reader is damaged. This GPS was not tested because the chart reader is obsolete. The receiver itself is probably extremely obsolete as well as it is a single channel receiver (our new GPS is a 12-channel receiver) that can take over an hour to aquire a position and does not use DGPS or WAAS.

Re-installation of this GPS receiver is NOT recommended.

Flux Gate Compass

The flux gate compass is located forward and to port of the nav station, above the port side water tank.

The flux gate compass has not yet been tested, but the cable from the compass was connected to the RADAR display and to the autonav system. The RADAR display is designed to take true heading data from a flux gate compass to convert relative bearings of targets to true or magnetic bearings.

This should be tested after the boat is splashed.

To Do

• Re-run the cable through the mast.
• Re-install the Radar antenna on the mast
• Fabricate a guard rail so the genoa doesn't get snagged on the antenna.
• Test and re-connect the flux gate compass.
• Route the NMEA output data from the Garmin GPS to the Radar display.
• Acquire an external monitor that can display the radar data in the cockpit.

Ted