Chapter 3  INSTALLATION OF THE DISPLAY UNIT 
3.8  CONNECTING TO THE GYRO AND ELECTROMAGNETIC LOG (NSK UNIT SETTING) 
3-22 
 Setting and adjustment of the NSK unit 
The NSK Unit of the radar equipment is designed to be compatible with almost all types 
of gyro compass by switch operation (For the step motor type, 20 VDC to 170 VDC, and 
for the synchro-motor type, the primary excitation voltage is 35 VAC to 120 VAC). 
Before power-on operation, the switches S1, S2, S3, S4, S5 and jumper TB105 on the 
NSK Unit shall be set to the type of gyro compass in use in accordance with the 
procedures as described below. The gyro select switch on the gyro I/F circuit is set to the 
gyration ratio of 180X and to be compatible with the step type before delivery from 
factory. Check the type of the gyro compass used in own ship and make settings in the 
procedures below.   
 
1  Set the switches of the NSK Unit before turning on the radar equipment. 
S1:  
Set it to [OFF]. 
S2 and S3:   
There are two types of gyro compasses: a compass of one type outputs a step 
signal, and the other outputs a synchro signal. Make sure of the type of gyro 
compass used with the own ship before setting S2 and S3. 
 
Synchro signal  ·································· Set it to [SYNC]. 
Step signal  ······································· Set it to [STEP]. 
 
S4:  
Set it in accordance with the S4 setting table. 
S4-1  ·············································· Set the LOG alarm. 
No LOG alarm  ·································· [OFF] 
LOG alarm  ······································ [ON] 
S4-2  ···························Set GYRO SIMULATOR. 
Set it to [OFF]. 
S4-3  ···························Set LOG SIMULATOR. 
Set it to [OFF]. 
S4-4 ···························Not used 
S4-5  ···························Set the time to the gyro alarm. 
0.5 seconds for gyro alarm  ···················· [OFF] 
5 seconds for gyro alarm  ······················ [ON] 
S4-6  ···························Set the sensor to be used. 
Using the gyro  ·································· [OFF] 
Using NMEA  ··································· [ON]