Longitude Error Table (On 96 Nm Range Scale - Furuno FAR-2107 Operator's Manual

Transceiver unit RTR-082 (for FAR-2837SW)
MD Board
(03P9244)
RF PWR Board
(03P9348)
RFC Board
(03P9346)
TB Board
(03P9349)

4. Longitude Error Table (on 96 nm range scale)

The longitude lines concentrate on the north pole and south pole, namely, 1 nm is
equivalent to 1 minute at 0 degree latitude, 2 minutes at 60 degrees latitude, 3 minutes at
70 degrees latitude and so on. For this reason, a longitude error occurs on the radar display.
For example, when own ship is at 60°N and 135°E, even if the cursor indication is 62°N and
139°E, the real cursor position is deviated to the left (west) side. The table below shows the
longitude error, represented from 0° to 90° at 96 nm from the radar center (own ship).
Real cursor position
62°N
60°N
135°E
Pulse Transformer
(RT-9273)
Transceiver unit RTR-082, cover opened
Cursor position
indicated
139°E
Distance error in direction of longitude due to latitude
Magnetron
(MG5223F)
Beneath plate
MIC Assy. (RU-9760A)
Circulator (RC4910S)
TR Limiter (TL378A)
Fan Motor (MSS-09B24DH-R)
IF Board (03P9335)
Real cursor position
°N
96 nm
θ
LAT
OS position
APPENDIX
R: Error
Cursor position
indicated
°E
AP-49