Yokogawa Denshikiki MKR181A Dual Channel Recorder (Heading & Rudder Angle Course Recorder)

Manufacturer	Yokogawa Denshikiki Co., Ltd. (now YDK Technologies), Japan
Product	Dual Channel Recorder (course / heading and rudder angle recorder)
Model	MKR181A
Mounting Type	Wall mount – MKR181A-W (suffix not shown on the label; 22 kg mass matches the wall-mount type in the manufacturer specification)
Mass	22 kg (nameplate)
Serial No.	0305
Date	2008.10
Marking	CE
Front Switches	RECORD START, SPEED FAST, LIGHT ON
Power Rating	Not clearly visible in the supplied photograph
Country of Manufacture	Japan
Condition	Refurbished
Supplier	SM MARINE SERVICE™, Chattogram, Bangladesh

Product Introduction

The Yokogawa Denshikiki MKR181A is a marine dual channel recorder that continuously records the ship's heading and rudder angle on paper chart – a course recorder for the bridge. SM MARINE SERVICE™ supplies refurbished Yokogawa MKR181A recorders and related spare parts to ship owners, ship managers and service companies worldwide. Visit https://www.smmarineservice.com/ for more navigation and communication equipment.

What Is This Equipment?

A course recorder creates a permanent record of the ship's heading and rudder movements. It is connected to the gyro compass and the rudder angle transmitter, and the chart is used for voyage records and incident investigation. The MKR181A is based on the Yokogawa μR20000 recorder and records heading (blue), quadrant (red) and rudder angle (green) with felt pens, while printing date, time and chart speed on the chart.

Main Features

• Continuous recording of heading, quadrant and rudder angle
• 180 mm Z-fold chart, approx. one month per chart at normal speed
• Two chart speeds: NOR 25 mm/h and FAST 250 mm/h
• VFD display with date, time and bar graphs
• Automatic printing of date, time and recording details
• Internal LED chart illumination for night use
• Password key lock and 10-year lithium memory backup
• AC 100–240 V or 24 V DC models; wall or flush mounting

Yokogawa Denshikiki MKR181A Dual Channel Recorder – refurbished, SM MARINE SERVICE™

Main Technical Specifications

Base Recorder	Yokogawa μR20000 microprocessor recorder, modified for marine use
Recorded Signals	Heading (blue), quadrant (red), rudder angle (green)
Inputs	0–5 V DC: heading per 90° sector, quadrant 1.25/2.50/3.75/5.00 V, rudder 0 V = Port 40°, 2.5 V = midship, 5 V = Stbd 40°
Accuracy	Heading ±1.2°; rudder ±1.2° or less
Dead Band	0.2°
Measuring Interval	125 ms per channel
Recording Method	Disposable felt pens
Chart Paper	180 mm wide, 20 m Z-fold
Chart Speed	NOR 25 mm/h, FAST 250 mm/h (approx. 1 month per chart at NOR)
Display	VFD 20 digits with date, time and bar graphs
Printing	Date, time, chart speed, tag names, values and units printed on chart
Power Supply	100–240 V AC 50/60 Hz (AC model) or 24 V DC (DC model)
Power Consumption	Approx. 17 VA (100 V AC) / 25 VA (240 V AC) / 70 VA (24 V DC)
Memory Backup	Lithium battery, approx. 10 years
Dimensions (W×H×D)	Wall mount 374 × 430 × 270 mm; flush mount 374 × 430 × 248 mm
Mass	Wall mount 22 kg; flush mount 12 kg
Operating Temperature	0 to 50 °C
Models	MKR181A-F (flush mount), MKR181A-W (wall mount)

Specifications from Yokogawa general specification GS 80B12R07E. Always check your unit nameplate.

Inside the Unit: PCBs, Modules & Part Numbers

The MKR181A is built around a Yokogawa μR20000 recorder module inside a marine case. The manufacturer's public specification does not list internal board numbers, so they are marked Not verified. Send us a photo of your board label for identification.

μR20000 Recorder Module

The internal Yokogawa μR20000 pen recorder: CPU, measuring inputs, pen drive and chart drive. Internal board part numbers: Not verified.

Terminal Board

Input terminals for heading, quadrant and rudder angle signals and power supply (shown in the specification wiring diagram). Part number: Not verified.

Power Supply Unit

AC 100–240 V or 24 V DC version. Part number: Not verified.

VFD Display Board

20-digit vacuum fluorescent display for date, time and bar graphs. Part number: Not verified.

Chart Illumination LED

Internal LED lighting of the chart, switched by LIGHT ON. Part number: Not verified.

Front Switch Panel

RECORD START, SPEED FAST and LIGHT ON switches. Part number: Not verified.

Lithium Backup Battery

Keeps clock and settings for approx. 10 years. Part number: Not verified.

Main Components & Related Units

• MKR181A-W wall mount and MKR181A-F flush mount recorders
• Related Yokogawa course recorders: MKR101A, KR180 dual channel recorder
• Yokogawa / YDK gyro compasses: CMZ700, CMZ900 series
• Yokogawa / YDK PT500 series autopilot
• Rudder angle transmitter and rudder angle indicator system
• Consumables: 180 mm Z-fold chart paper and felt pens (blue, red, green)

Marine & Industrial Applications

• Bridge course recorder for heading and rudder angle on merchant ships
• Integration with gyro compass and steering gear / autopilot systems
• Voyage and incident records for owners, class and flag
• Replacement of a failed course recorder on existing Yokogawa installations

Nameplate: Dual Channel Recorder, Model MKR181A, Mass 22 kg, Ser. No. 0305, Date 2008.10, Yokogawa Denshikiki Co., Ltd., Made in Japan

Common Problems & Troubleshooting

• No trace on chart: check felt pens, pen fitting and chart paper loading.
• Chart not moving: check RECORD START switch, chart speed and chart drive.
• Wrong heading or rudder trace: check the 0–5 V input signals from the gyro and rudder transmitter, and the input wiring.
• Wrong date or time: check the lithium backup battery (low battery indication on the front panel).
• No display or no power: check AC / 24 V DC supply, fuses and power supply unit.

Safety note: isolate the power supply before opening the case or working on terminals. Work should be carried out by a qualified marine electronics technician.

Maintenance Tips

• Replace felt pens and chart paper before they run out
• Keep the chart window and front door clean
• Check date and time regularly
• Check input signals against the gyro and rudder angle indicator
• Store used charts as voyage records

Spare Parts & Replacement Availability

SM MARINE SERVICE™ supplies refurbished Yokogawa MKR181A recorders and can source parts and consumables on request. For a fast quotation, please send:

• Model (MKR181A-W or MKR181A-F) and serial number
• Nameplate photo and power supply type (AC or 24 V DC)
• Photo of any faulty board or part
• Vessel name and delivery port

We ship worldwide by courier and air freight to ports in Asia, the Middle East, Europe, Africa and the Americas.

Why This Equipment Is Still Used

The MKR181A is installed on many ships with Yokogawa gyro and steering systems. An identical replacement fits the existing mounting, wiring and input signals, so the course recorder can be restored quickly without changing the bridge installation.

FAQ

What does the Yokogawa MKR181A record?

It continuously records the ship's heading, heading quadrant and rudder angle on a 180 mm paper chart.

Is the MKR181A a course recorder?

Yes. It is a dual channel course recorder for heading and rudder angle, used with gyro compass and steering systems.

What is the difference between MKR181A-F and MKR181A-W?

-F is the flush (panel) mount type (12 kg); -W is the wall mount type (22 kg).

What chart paper does it use?

180 mm wide, 20 m Z-fold chart paper; one chart lasts about one month at normal speed.

What are the chart speeds?

NOR 25 mm/h and FAST 250 mm/h.

Which recorder is it based on?

The Yokogawa μR20000 microprocessor recorder, modified for marine use.

Do you have PCB part numbers for the MKR181A?

The public specification does not list board numbers. Send us photos of the board labels and we will check.

What input signals are needed?

0–5 V DC signals for heading, quadrant and rudder angle, normally from the gyro compass and rudder angle transmitter system.

What power supply does it need?

100–240 V AC or 24 V DC, depending on the model.

What do you need for a quotation?

Model, serial number, nameplate photo, vessel name and delivery port.

Do you ship worldwide?

Yes. SM MARINE SERVICE™ ships worldwide from Bangladesh and China.

Short Product Description

The Yokogawa Denshikiki MKR181A is a Japanese marine dual channel recorder that continuously records ship heading, quadrant and rudder angle on 180 mm Z-fold chart with felt pens. Based on the Yokogawa μR20000 recorder, it offers NOR 25 mm/h and FAST 250 mm/h chart speeds, a VFD display, automatic date and time printing and LED chart lighting. It works with 0–5 V DC heading and rudder signals from gyro and steering systems and is available as MKR181A-W (wall mount) or MKR181A-F (flush mount). SM MARINE SERVICE™ supplies refurbished MKR181A course recorders worldwide.

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SM MARINE SERVICE™ – Marine Automation & Navigation Equipment Supplier

Available Equipment Conditions: New • Used • Refurbished • Reconditioned (Specific product condition and availability are subject to confirmation.)
Stock Locations: Bangladesh • China
Services: Worldwide Shipping • Technical Support • Spare Parts Supply • Marine Equipment Sourcing
Samir Market, DT Road, Pahartali, beside CDA Market, Chattogram, Bangladesh
Mobile / WhatsApp / Viber: +88 01818 929292
Email: info@smmarineservice.com
Website: https://www.smmarineservice.com/

Send us your model, serial number and photos today for a quick quotation on the Yokogawa MKR181A course recorder and spare parts.

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