190-01007-A1 System Maintenance Manual GTN 6XX/7XX Part 23 AML STCRev. 5 Page 7-117.4.1.1.1.1 Main Indicator OBS Resolver CalibrationTo calibrate the OBS resolver, touch the Calibrate key from the Main Indicator Configuration page. Next,select 150˚ on the External CDI/HSI then touch the OK key, as prompted on the display. After the OBSresolver is finished calibrating, the GTN will display “OBS Resolver Calibration Complete!” Touch OKafter the calibration is complete. Verify OBS operation by checking that the selected course displayed atthe top of the page is within 2° of the selected course.The Main Indicator (Analog) Configuration page allows the CDI connected to the NAV board (P1001) tobe ground checked and allows the NAV indicator interface to be verified. See Section 7.4.1.2.1 for theground check.7.4.1.1.2 VOR/LOC/GS Configuration Page(GTN 650/750 Only)Select the VOR/LOC/GS key on the GTN Setup page. Thispage allows you to verify the CDI outputs from theVOR/LOC/GS receiver as well as the OBS resolver input tothe VOR receiver. It also allows you to select the format forthe DME tuning data.7.4.1.1.2.1 Calibrate OBS ResolverTo calibrate the OBS resolver, touch the Calibrate key fromthe VOR/LOC/GS Configuration page. Next, select 150˚ onthe external CDI/HSI, then touch the OK key whenprompted by the display. Touch OK after calibration iscomplete. Verify OBS operation by checking that theselected course displayed at the top of the page is within 2°of the selected course.Figure 7-3. VOR/LOC/GSConfiguration Page
