Furuno FR1500 Mk3 User Manual download pdf (Page 95)

-7.1-

7 OPTIONAL EQUIPMENT

7.1 Performance Monitor (Option)

A performance monitor is required for a radar installed on certain type of ship as determined by the

Administrations. The FURUNO PM-30 (for X-band radars) covers 9410 ± 50 MHz.

It works on the transponder principle. It sends response back to the radar antenna upon receiving

the pulse from the radar antenna and determines if transmitter or receiver or both are deteriorated in

comparison with the state of the precious calibration.

Operating the performance monitor

1. When Radar Interswitch is connected (depending on the type), set it to the "straight" mode.

2. Press [F1], [9] keys in this order. Monitoring arcs do not harm the radar performance but if they

disturb to radar observation, turn it off by pressing [F1] [9]. ([F1] [9] toggles Performance

Monitor ON and OFF.)

3. When the Performance Monitor is on by [F1], [9] the following condition results:

PM power: ON, IR: OFF, ECHO AVG: OFF, ES: OFF, A/C AUTO: OFF, N REJ: OFF,

RANGE: 24 nm

Wait for 10 minutes and the radar screen will show several arcs, opposite to the heading marker

(provided that the performance monitor is installed behind the radar antenna as is normally the

case). If the radar transmitter and receiver are in good working conditions in as much as the original

state when the monitor was tuned up, the innermost are should appear at 12 nm and there should

be a total of 4 arcs.

The range of the innermost arc reduces 3 nm with every 3 dB loss of transmitted power. Receiver

sensitivity can be evaluated from the number of visible arcs; one arc is lost every 3 dB deterioration

of the sensitivity.

Transmitter performance Receiver performance

Range to innermost arc Loss Number of arcs Loss

12 nm 0 dB 4 0 dB

9 nm 3 dB 3 3 dB

6 nm 6 dB 2 6 dB

3 nm or less or none > 10 dB 1 > 9 dB

0 > 12 dB

1 2 ... 90 91 92 93 94 95 96 97 98 99 100 ... 119 120

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Furuno FR1500 Mk3 User Manual Page 95