Optional Equipment; Performance Monitor (Option) - Furuno FR-1500 MARK-3 Series User Manual

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
Range to innermost arc
12 nm
9 nm
6 nm
3 nm or less or none
Loss
0 dB
3 dB
6 dB
> 10 dB
-7.1-
Receiver performance
Number of arcs
4
3
2
1
0
Loss
0 dB
3 dB
6 dB
> 9 dB
> 12 dB