SECTION TWO - Installation961 INSTALLATION MANUAL Revision A Page 9Choosing a system locationThe 961 consists of two major parts—a processor and a control head. The961 supports two fully functional control heads (the second head isoptional). The 961 system comprises the processor and control head, GPSreceiver, optional differential receiver, controls, and the specially-coateddisplay screen.Mounting thecontrol headYou can either yoke- or flush-mount the control head: Use theyoke-mount kit as a framework for holding the control head, orflush-mount the control head directly onto a flat surface of your choice.Using the Northstar-supplied yoke mounting kit usually provides aquicker and less expensive installation than a flush-mount installation.Regardless of the type of mount, here are a few helpful hints about whereto mount the control head. Choose the mounting location care-fully—before any drilling or cutting takes place. Choose a location that:• is convenient, accessible, and within comfortable reach• gives you easy access to the function keys• is where you can clearly see the display screen from your normalvantage point when navigating• for best display contrast, is viewed from below, looking up at thedisplay screen• provides a reasonably direct path for running the required electricalcables• has minimal glare from windows or other bright objects (eventhough the unit has a high-contrast, anti-reflective LCD screenthat’s specially coated and readable in direct sunlight, you’ll want tomake the screen as visible as possible)• if flush-mounting the head, make sure you choose an area that’swell-ventilated; poor ventilation may cause overheating, resultingin potential backlighting problemsYoke mountingFor yoke mounts, leave ample room—usually two inches—all around thesides and top to avoid crowding the unit. Also allow a clearance of at least2½ inches in the rear just for the cables and connectors. For the recom-mended yoke-mount installation dimensions, see Figure 1, and Figure 2.Before drilling holes, rotate the unit to the desired angle to ensure properclearance for cables and operation of the unit.