1. Circuit Description
1
GP-90 features;
1) WAAS-capability (From the production in December 2003)
2) Compliance of IEC61108-1 ed.2
3) Calculation of set and drift based on NMEA ground speed and heading data (From the
production in December 2003)
4) Entering waypoint in range and bearing data (From the production in December 2003)
1.1 Antenna Unit
The antenna unit includes a preamplifier. The antenna cable c5 V to power the preamplifier.
The GPS signal received by the antenna is delivered to the GPS board, GN-8091. The GPS board
selftest cannot detect the short circuit on the antenna cable.
1.2 Display Unit
Figure 1 shows the block diagram of the display unit.
PREAMP
Beacon Antenna
ANTENNA UNIT
DISPLAY UNIT
Lat/Long, SPD/CRS
GPS initial data
LCD
Key Data
LED Brill,
Display Data
+24 V,
AC210 V
GN-8091 Board
GPS
Power supply
PNL Board
(20P8148)
Keyboard
BEACON
Receiver
(GR-7000A)
+5V,+12V
NP Board
(20P8188)
RTCM SC-104
10.2 - 31.2 V
+5 V
Fig. 1 Block diagram of GP-90
RX SIG
5 V
