Gsu 75B, Grs 77, Or Grs 7800 Earth Magnetic Field Updates; Gsa 80 Greasing Procedure - Garmin G1000 Nxi System Maintenance Manual

Test points are between the inside connector body and nearby exposed structure with coaxes
disconnected.
• GA 36 (GPS #1): __________ mΩ
• GA 37 (GPS #2): __________ mΩ
• GA 58 (GTS Traffic): __________ mΩ

GSU 75B, GRS 77, or GRS 7800 Earth Magnetic Field Updates

The GSU 75B, GRS 77, or GRS 7800 utilizes an Earth magnetic field model which is updated
once every five years. The update is expected to be available from Garmin every five years, as
long as the GSU 75B, GRS 77, or GRS 7800 remain Garmin-supported products.
The G1000 system alerts the operator that the magnetic field database is out of date by issuing
the message "AHRS SERVICE – AHRS Magnetic-field model needs update". Garmin will
distribute updates as part of the navigation database cycle. If the IGRF model in the update is
newer than the model installed, a prompt will appear for each GRS/GSU (Select "OK" to update
the IGRF Magnetic Field Model). Use the FM Knob and ENT key to select "OK".

GSA 80 Greasing Procedure

The GSA 80 servo greasing procedure is required only when the GSA 80 is removed and
reinstalled. Refer to Section 6.12 for details.
G1000 NXi System Maintenance Manual
King Air 300 Series
190-00716-N1
Antennas
Page 117
Revision 1