JRC JMA-5212-4/6 User Manual page 124

[II] Parallel Index Line Bearing (Reference Bearing)
Parallel index line bearing mode can be switched.
Procedure 1
2
* Bearing in the parallel index line menu will show which is selected,
true bearing or relative bearing.
Press [RADAR MENU] key.
Press [3] key.
Press [5] key.
Press [3] key.
The Parallel Index Line Menu will appear.
Press [2] key.
The Reference Bearing mode is switched
between true bearing and relative bearing each
time you press [2] key.
3 45