The FURUNO PM-50 Performance Monitor is a mandatory ancillary device designed for S-band (3050 ± 30 MHz) marine radar systems. Required by SOLAS for vessels of 300 GT and upward engaged in international voyages, this unit allows crews to quickly verify radar transmitter power and receiver sensitivity without leaving the bridge.
Unlike integrated diagnostic tools, the PM-50 operates as a fully independent unit (requiring only a 100 VAC power connection), ensuring that radar performance checks remain unbiased by the radar’s own electronic systems.
Key Features & Technical Specifications
1. S-Band Frequency Coverage
Specifically tuned for 3050 ± 30 MHz, the PM-50 fulfills the specific testing requirements for S-band (3 cm) navigation radars used in heavy weather and long-range detection.
2. Independent Operation
- No Interconnection: The PM-50 is not connected to the radar’s signal processing or interswitch units (except for power).
- Automatic Range Scaling: Upon activation, it automatically sets the radar range scale to 24 nm and generates a predictable target pattern (arcs) on the display.
3. Dual-Function Diagnostics
The PM-50 provides simultaneous testing of both transmission and reception:
- Transmitter Test: Measures power loss by tracking the movement of the innermost arc (baseline: 12 nm).
- Receiver Test: Measures sensitivity loss by counting the number of visible arcs (baseline: 4 arcs).
4. Simple Performance Evaluation
The monitor offers a straightforward, visual pass/fail matrix:
| Transmitter Status (Innermost Arc Range) | Loss | Receiver Status (Visible Arcs) | Loss |
|---|---|---|---|
| 12 nm | 0 dB | 4 Arcs | 0 dB |
| 9 nm | 3 dB | 3 Arcs | 3 dB |
| 6 nm | 6 dB | 2 Arcs | 6 dB |
| 3 nm or less | >10 dB | 1 Arc or None | >9 dB |
Table data compiled from official FURUNO technical manuals.
Compliance & Regulatory Info
- SOLAS Regulation: Required for vessels subject to SOLAS Chapter V (Safety of Navigation).
- GT Requirement: Mandatory for vessels 300 GT and upward (GMDSS) and 500 GT for non-GMDSS vessels.
- Compatibility: Specifically designed for FURUNO S-band radar systems (e.g., FR-2105 series, FAR-2805 series).
Installation & Operation
The PM-50 is typically installed behind the radar antenna (scanner). To operate:
- Connect the 100 VAC power cable.
- Press the PM ON/OFF button.
- The radar will automatically switch to the 24 nm range.
- Evaluate the arcs appearing opposite the heading marker.
