Furuno FR-8251, FR-8111 Tuning the Receiver, Adjusting Sensitivity, Adjusting Picture Brilliance

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1.6 Tuning the Receiver

The receiver can be tuned automatically or manu- ally. The default (factory setting) is automatic tun- ing.

Selecting tuning mode

1)Press the MENU key.

2)Select the INITIAL menu.

3)Press the ENTER/SELECT key.

Note: The above three steps can also be done by pressing and holding down the MENU key.

4)Select TUNE SET and press the ENTER/SE- LECT key.

5)Select AUTO (or MANUal).

6)Press the ENTER/SELECT key.

7)Press the MENU key.

Manual tuning

1)Select manual tuning by following "selecting tuning mode."

2)While pressing and holding down the HM OFF switch, adjust the trackball to display the long- est tuning indicator.

Tuning indicator

MANUAL

Video lockup recovery

Video lockup or picture freeze, can occur unex- pectedly on digital rasterscan radars. This is mainly caused by heavy spike noise in the power line, and can be noticed by carefully watching the nearly invisible sweep line. If you suspect that the picture is not updated every scan of the antenna or no key entry is accepted notwithstanding the apparently normal picture, turn the power off and on.

1.7 Adjusting Sensitivity

The GAIN control adjusts the sensitivity of the receiver and thus the intensity of echoes as they appear on the screen.

The proper setting is such that the background noise is just visible on the screen. If you set up for too little sensitivity, weak echoes may be missed. On the other hand excessive sensitivity yields too much background noise; strong targets may be missed because of the poor contrast be- tween desired echoes and the background noise on the display.

To adjust receiver sensitivity, transmit on long range, and adjust the GAIN control so background noise is just visible on the screen.

1.8 Adjusting Picture Brilliance

The BRILL control adjusts the brilliance of the picture.

Figure 1-7 Display appearance when

manual tuning is in effect

Note: The receiver may be detuned if your radar is hit by another radar in vicinity. To retune in automatic tuning, press the ST BY/TX key twice.

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Contents Marine Radar 00080735211 Safety Information Do not diassemble or modify the equipment Radio Frequency Radation Hazard IiiUse the correct fuse Compliance with R&TTE Directive 1999/5/EC Table of Contents Maintenance Vii Features Word to FR-8051/8111/8251 OwnersForeword Configuration of FR-8051/8111/8251 Transceiver Module SpecificationsAntenna Unit Environmental Conditions Power Supply and Power ConsumptionDisplay Unit OthersXii Equipment ListsStandard Set Xiii Optional EquipmentSpare Parts Categorization by Specification XivOperation Control DescriptionDisplay Indications 25 NMDisplay indications lower part Transmitting, Stand-by Turning the Radar On/OffSelecting Range Presentation Mode Selecting presentation modeDescription Changing pages on the Initial menu Menu OverviewBasic menu operation Menu tree MK Erase erase all fixed marksInitial Tune SET AUTO, Manu SPD Mode MAN, LOG, NAV Adjusting Picture Brilliance Tuning the ReceiverAdjusting Sensitivity Selecting tuning modeSuppressing Sea Clutter Adjusting Brilliance of Control Panel and MarkersAdjusting Range Ring Brilliance Automatic anti-clutter controlMeasuring the Range Suppressing Rain ClutterHeading and North Markers Measuring range by the range ringsMeasuring Bearing Canceling the cursor offset Collision Assessment by Measuring Range Offset EBLIndex Lines Off-centering the PictureFunction key ZoomInscribing Marks on the Display Automatic speed input Own Ship SpeedTurning on a function Echo Trails Ship’s GraphicInterference Rejector Manual speed inputTrail time Canceling echo trailStarting echo trail Trail referencePlotting a target Electronic Plotting E-plotTrail brilliance True or relative vector Canceling target plottingTarget data Vector timeSelecting guard zone type Setting a Guard Alarm ZoneSetting a guard zone Activating the guard zonesCanceling the guard zone and guard alarm Watch AlarmSilencing the aural alarm How to turn on echo averagingSuppressing Second-Trace Echoes 26 Echo averageNoise Rejection Presetting pulselengthEcho Stretch Selecting PulselengthSelecting pulselength set to use Waypoint DisplayOutputting Cursor Position TLL data Sector Blanking Alarm Output Signal On/OffSelecting Unit of Range Measurement, Bearing Reference This page is intentionally left blank Radar Picture, Target Properties and Radar Pulse Range ResolutionRadar Observation Indirect echoes Bearing ResolutionFalse Echoes Multiple echoesMinimum range Minimum and Maximum RangesSide-lobe echoes Blind and shadow sectorsLocating a Ship or Survival Craft in Distress by Sart Gain This page is intentionally left blank Maintenance When Working on the Antenna UnitPeriodic Maintenance Schedule Troubleshooting Simple TroubleshootingAdvanced-level Troubleshooting Serviceman qualificationProblem Check point and probable Remedy Cause Problem Check point and probable Remedy Cause Diagnostic Test Diagnostic test, test patternThis page is intentionally left blank Location of Parts Antenna UnitRF Transceiver Unit Modulator TriggerRF transceiver unit FR-8051/8111 Display Unit common to all models Display unit, top viewDisplay unit, right side view This page is intentionally left blank Performance Monitor Operating a performance monitorFluxgate Heading Sensor C-2000 Auto Plotter ARP-15Video Plotter RP-15 Page

FR-8251, FR-8111 specifications

Furuno has long been a leader in marine electronics, and its FR-8251 and FR-8111 radar systems continue that tradition. Both are advanced systems designed specifically for professional mariners who demand high performance, reliability, and technological sophistication in their navigational tools.

The Furuno FR-8251 is a powerful radar system that boasts a range of features tailored for commercial vessels. With a 25 kW transmitter, the FR-8251 delivers exceptional performance, providing a clearer and more detailed image of the maritime environment. It is equipped with advanced signal processing technology, including the Doppler processing feature, which allows for the detection of moving targets. This is highly beneficial for collision avoidance, as it provides accurate information regarding the speed and direction of other vessels.

Another noteworthy feature of the FR-8251 is its large, high-resolution display that enhances visibility and ease of use, even in challenging weather conditions. The user interface is straightforward, allowing for quick adjustments and easy navigation through the various settings. It supports a variety of display formats and allows for customization, enabling operators to tailor the information presented according to their specific needs.

On the other hand, the Furuno FR-8111 is equally impressive and designed as a more compact solution without sacrificing performance. This model comes with a 12 kW output and is specifically crafted for smaller vessels, yet it still delivers high-quality radar coverage. Utilizing Furuno’s renowned Automatic Target Tracker (ATT) technology, the FR-8111 enables mariners to efficiently track multiple targets, significantly enhancing situational awareness.

Additionally, both the FR-8251 and FR-8111 come with integrated ARPA (Automatic Radar Plotting Aid), providing users with sophisticated tools for navigation and collision avoidance. The presence of multiple target tracking empowers operators to make informed decisions, optimizing safety at sea.

Furuno’s commitment to reliability and durability is evident in both models, which are designed to withstand the harsh marine environment. Their robust build quality ensures longevity, while their advanced technologies offer peace of mind.

Both the Furuno FR-8251 and FR-8111 are excellent choices for professional mariners seeking cutting-edge radar systems. With their impressive performance, user-friendly interfaces, and advanced technologies, these radar systems set the standard in marine navigation, providing essential support for safe and efficient voyages.
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