The Koden CVS-872D is a compact digital echo sounder / fish finder designed for small fishing vessels, workboats, and coastal operations. It is part of Koden’s CVS series and is known for its simple operation, reliability, and clear underwater imaging.

The CVS-872D works by:

Transmitting ultrasonic sound pulses (typically 50/200 kHz)
Receiving echoes from:
- Seabed
- Fish schools
- Underwater objects
Converting signals into:
- Digital depth reading
- Echogram (bottom profile)
- Fish target display

Technical Specification

📊 Technical Specifications

🖥️ Display

Screen size: 12.1-inch
Type: Color XGA LCD
Resolution: 1024 × 768 pixels

⚡ Transmitter / Sonar Performance

Output power (RMS): 1 – 3 kW (depends on transducer)
Transmission rate: Up to 1500 pulses/min
Pulse width: 50 µs – 3.0 ms

📡 Frequency

Selectable frequency range: 24 kHz – 240 kHz (0.1 kHz steps)
Operation modes:
- Single frequency
- Dual frequency
- Triple frequency
- Quad frequency (simultaneous or alternate)
Typical transducer frequency bands:
- 38–75 kHz
- 80–130 kHz
- 130–210 kHz
- 50/200 kHz (depending on model)

🌊 Depth & Range

Depth range:
- 1 – 3000 meters
- 5 – 8000 feet
Zoom range:
- 1 – 260 meters
Shift range:
- Up to 3000 meters

🧠 Processing & Functions

Digital filtering: Koden KDF™ (low noise / high sensitivity)
Key functions:
- Interference rejection
- Noise reduction
- White line (bottom separation)
- Color erase
- Bottom hardness display (%)
- Draft, temperature & speed correction
- Heave compensation
- Event memory & homing
- Simple plotter
- Sona-Tone™ audio detection

💾 Memory & Storage

Image storage: Up to 500 screenshots
Condition Memory: 6 preset configurations

📊 Display Modes

High / Low frequency views
1–4 frequency split screens
Zoom modes:
- Bottom lock
- Bottom discrimination
- Bottom zoom
- Bottom follow zoom
Vertical / horizontal split
Mixed display modes

🎨 Display Colors

Color palettes: 64 / 16 / 8 colors + monochrome
Background options: marine blue, black, white, night mode, etc.

🔌 Interfaces & Data

NMEA input/output: NMEA 0183 (ver. 1.5 / 2.0 / 3.0)
Supported data:
- GPS (GGA, RMC, etc.)
- Heading (HDT)
- Speed (VTG, VHW)
- Water temp (MTW)
Ports: 2 (input + output)