MARINE RADAR EQUIPMENT JMA-3204/3210/3211 CR WIRE) Gepecue actin (1, Led, INSTRUCTION MANUAL » "esa ft pce es ety. ene ‘tiedCAUTIONS FOR HIGH VOLTAGE High voltages ofhundreds upto thousands volt are used in radio and radar devices. Although prudent measures'for:safety have been: adopted, sufficient cares should be taken on operation, maintenance and adjustment of fh device. Electric shock by thousands volt leads to an instantaneous death for certain, and even electric shock by hundreds voll fedNho’ ‘ah initantarieous death occasionally. To prevent such an accident, turn off the power source diWeharye capacitors by a wire surely earthed at one énd, and check that any charge is no longer inside the device, before you put your hand into the inside. It is stil better to wear dry wool @léved oom caiition tot to use both hands S'1nutaneously, by putting the one hand int6 spem Alp od j The selection of Stable foothdld igressential to prevent more extensive or additional When injured by electricishoeRedisinfeet the burn perfectly aiid give first aid’as soon'as possible. Some person ailérgic to dust may temporarily be affected in health, if he inspires dust scattered at the time of cleaning theradaningides: ‘ iGdaios "RADIATION HAZARD If the human body is exposed to a microwave of 10mW/cm? in mean power density, it will be affected, in particular, at the eves. Do not approach to any antenna’ @uring standstill as near as 60cm or less. If it is unavoidable by any means to disconnect a microwave transmission line upon the mainte- nance or checks, always connect a microwave dummy load to associated radar transmitter. If it is unavoidable to radiate the microwave without using any microwave dummy load, never peep the active waveguide into its end during transmission, since the end is open.WHAT TO DO IN CASE OF ELECTRIC SHOCK When a victim of electric shock is found, turn off the power source and earth the circuit im mediately. If this is impossible, move the victim away from it without touching him with bare hands as quick as possible. He can safely be moved if an insulating material such as dry wood plate or cloth is used, Breathing may stop if current flows through the respiration center of brain due to electric shock. If the electric shock is not large, breathing can be restored by artificial respiration. A victim of electric shock looks pale and his pulse becomes very weak or stops, resulting in unconsciousness and rigidity. FIRST-AID TREATMENTS As far as the victim of electric shock is not in dangerous condition, artificial respiration should be started at once at the site. Once started it should be continued rythmically, 1) Do not touch the victim confusedly or rescuer may also receive an electric shock. 2) Turn off the power source and move the victim from the electric line calmly. 3) Call a physician or ambulance immediately, or instruct someone else to call 4) Place the victim on his back and loose his necktie, clothes, belt, etc. Examine the victim's pulse. Examine the heartbeat by laying your ear on his heart. Examine breathing by bringing your face or back of hand close to his face. Examine the victim's pupils. peep 6) Open the victim's mouth and remove the artificial teeth, cigarette or chewing gum, if any. Keeping the mouth open, stretch the tongue and insert a towel or the like to prevent the tongue from suffocating. (If it is hard to open the mouth with set teeth, open it by a screwdriver and insert a towel.) 7) Wipe the mouth to prevent foamable mucus and saliva from accumulatiIN CASE PULSE CAN BE DETECTED BUT BREATHING STOPS (Mouth to mouth artificial respiration) a) Tilt the victim's head back as far as his face looks back. (A pillow may be inserted under the neck.) b) Pull the jaw into jutting position to open the throat. ©) Pinch the victim’s nostrils shut and place your mouth tightly over his after drawing your breath long. Then blow into mouth strongly. Continue blowing at a rate of 10-15 breathes a minute. 4) Watch carefully and continue artificial respiration till natural respiration is restored. ©) If the opening of mouth is difficult, insert a vinyl pipe or the like into a nostril and blow into it by shutting the other nostril and mouth perfectly. f) Victim may stand up suddenly when he becomes aware. He should lie quietly and kept warm and calm, Serve him with hot coffee or tea (but never alcoholic drinks). Fig. 1 Method of Mouth to Mouth artificial rospiration Tilting Back of Victim's Head Put one of your hands on the victim's fore- head and the other under the neck @. In general his mouth opens when the head is tilted back, making easy mouth to mouth artificial respiration. Place your mouth tightly over his and press your cheek against his nose @ or pinch his nostrils by your fingers @ to prevent air lea- kage. Blowing into Lungs Blow into the mouth till the chest rises. The first 10 breathes should be performed as fast as possible.a) b) ° a e IN CASE OF CARDIAC ARREST AND CESSATION OF BREATHING (Cardiac massage and mouth to mouth artificial respiration) When no pulse can be detected, the pupils are open and no heartbeat is heard, cardiac arrest is considerable. Therefore, artificial respiration should be started at once. Put the heel of one hand over the lower 1/3 of his breastbone and the other hand on the back of the first. Apply your weight so that the braestbone is compressed by about 2cm. (Repeat it at a rate of about 50 times a minute.) (Cardiac massage) In case of one rescuer After about 16 times cardiac massages, give mouth to mouth artificial respiration 2 times, and repeat them in this manner. In case of two rescuers While the victim is massaged, another person should give mouth to mouth artificial respira- tion. A breath is interposed after 5 cardiac massages. (Cardiac massage and mouth to mouth artificial respiration) Examine the pupils and pulse often. When they become normal, stop the first aid treatments, serve the. victim with coffee or tea and keep him warm and calm, while watching him carefully. Commit the victim to a medical specialist, according to the situation. For earlier recovery of the victim from the mental shock, the understanding of bystanders is essential. Fig. 2SECTION 1 SECTION 2 SECTION 3 SECTION 4 1 12 21 22 23 24 31 32 41 42 43 CONTENTS GENERAL DESCRIPTION 0. a 1d INTRODUCTION meet SPECIFICATIONS .. 1.2.1 General 1.2.2 Scanner Unit 1.23 Display Unit 1.24 Rectifier Unit 1.25 Cable Length Limits between Units .. 1.26 Options ... OPERATION 21 OPERATION 21 2.1.1 The Controls 24 2.1.2 Funetion of Controls... 22 2.1.3 Operating Procedure ... 217 MEASUREMENT ..... 218 2.2.1 Range Measurement .. 218 222 Bearing Measurement 219 USING THE CONTROLS 221 READING THE SCREEN 222 MAINTENANCE... o 31 GENERAL MAINTENANCE 31 MAINTENANCE OF EACH UNIT 32 3.2.1 Scanner Unit... soe 32 3.2.2 Display Unit . 37 MOUNTING AND INSTALLATION... al GENERAL a INSTALLATION OF SCANNER UNIT 4.2.1 Selecting the Installation Location 4.2.2 Installation 4.2.3 Connection of Cable .... INSTALLATION OF DISPLAY UNIT 4.10 431 Selection of Installation Location ... sen so 4.10 4.32 Installation Method 7 . 4-10 4.3.3 Modification Procedures for Over-head Installation and Well Type Installation ...... 4n4a 45 46 SECTION 5 51 52 53 SECTION 6 [OPTIONAL UNIT] CABLE REQUIREMENTS ..... a 4.4.1 Connection for Inter-Unit Cable 44.2 Power-Input Cable sonnntnnen MEASURES AGAINST NOISE IN RADIO COMMUNICATION EQUIPMENT 45.1 Shielding of the Units — 45.2 Connecting Cable between Units 4.5.3 Installation Position 454 Grounding ..... CHECKS AND ADJUSTMENTS AFTER INSTALLATION 46.1 Checking the Installation... 4.6.2 Checking Operations nnn 4.6.3 Adjustments 46.4 Rectifier ADJUSTMENT AND REPLACEMENT ADJUSTMENT... 5.1.1 Checking the Installation . 5.1.2 Initial Operation and Checkout 5.1.3 Erasing Way of Memory Contents by Battery Backed up REPLACEMENT 5.2.1 Adjustments when Parts Replacement have been made .. 5.2.2 Spare Parts TROUBLESHOOTING 53.1 General . 53.2 Fault Finding : 5.33 Typical Voltages and Resistances PARTS LIST NCT-27 NSK UNIT INSTRUCTION MANUAL 55 .. 56 413 413 419 422 422 4.22 422 422 423 423 ws 423 423 423 51 56 510 512 512 .. 52 515 61SECTION 1 GENERAL DESCRIPTION 1.1 INTRODUCTION Congratulations on selecting the JRC Model “JMA-3204/3210/3211" Raster Scan Radar for your radar navigation needs. Whether you've selected the JMA-3204/3210/3211 for its High-Resolution 12” monochrome radar display, ease of operation, or long term re- liability and high quality, we feel sure that you will enjoy many years of safe navigation. The JMA-3204/3210/3211 have a reliable 4 kW or 10 kW transmitter with three or four pulse- lengths, and four PRF's, the linear receiver has two bandwidths. The JMA-3204/3210/3211 will present an easy-to-see, high-definition video in green multi-gradations. Radar video intensities, from weak to strong, can be discriminated, and targets under rain and sea clut- ters can be clearly and distinctly displayed. The display may be operated in Relative mo- tion, with Head-up, North-up, or Course-up mode. The radar has two VRM’s with 4 digits digital readout from 00.00 nm to 63.40 nm or 95.10 nm (00.00 km to 117.4 km or 176.1 km). The radar has two EBL's with 4 digits digital readout from 000.0° to 359.9°. Other data and function which may be displayed is own ship’s L/L, TD, WPT, and Alarm Area. JMa.soo4 Sip Mans pewv [perv | —pewv [a= Model Thin S008 Scanner Un NKE-1022 Display Unt | NoD-1323 Rectifier Unit NBATHT JMaseio Sips Mains peav [ben [peeve Mosel TMASz0 Scanner Un KE 1028 Display Unit Nob-1323 Rectifier Ui MATa Iason Ship's Mains bei2 V be2z4 V DC32 V ACN Model Tai Seamer Ua NRE 1004-476 Display Uni Nob. Tectier Unit I NAIVE Note: Ship's mains is in AC condition —ACI100/ 110/115 V or AC20012201230 V, 50160 Hz, 1p1.2. SPECIFICATIONS 121 General » 2) 3) 4) 5) 6) 2 8) 9» 10) i) 12) 13) 14) 15) 16) Form of Radio Wave Display Method Display Screen Ranges Range Resolution Minimum Range Bearing Accuracy Bearing Resolution Display mode Display Color Enviconmental Condition Power Input Voltage Power Consumption Permissible Variation In Power Input Pre-heating Time From Preparation to Operation : PON Raster scanning, PPI display : 240%180 mm, high resolution 12” monochrome CRT Effective tube diameter 180 mm 20.25, 0.5, 0.75, 1.5, 3, 6, 12, 24, 48 nm (MA-3204) 0.25, 0.5, 0.75, 1.5, 3, 6, 12, 24, 48, 72 nm GMA- 8210/JMA-3211) : Less than 30 m : Less than 35 m : Less than 1° (0.1° unit for EBL) : Less than 2.7° (3.5 ft.) (MA-3204, JMA-3210) Less than 2.2 (4 ft.) (MA-3211-4) Less than 1.5° (6 ft.) GMA-3211-6) : Head up North up (with the bearing device; GYRO-NSK, LORAN C etc.) Course up (with the bearing device; GYRO-NSK, LORAN C ete.) een (phosphor P39) : Temperature Scanner unit: ~25 to +55°C (for rated input) (—25 to +70°C when not in use) Other units: 15 to +55°C (for rated input) (718 to +45°C when max. input) Relative humidity All units: 95% at +40°C :DC12 V, DC24 V, DC32 V, ACT : JMA-3204 JMA-3210 JMA-3211 pei2 Vv; 1A 10A 2A DC24 V; 5A 5A 6A DC32 V; 3.5.8 358 458 AC100/110/115 V, 200/220/230 V, 50/60 Hz, 19, approx. 270VA = 270 VA 300 VA * The NBA-797 Rectifier is necessary for AC input. : For max. cable length, at input terminal of Display unit DC12ZV 10.8 V~20 VDC DC24V 20 V to 42 VDC DC32V_ 20 V to 42 V DC AC +15% : Approx. 90 seconds. (MA-3204, JMA-3210) 3 minutes (MA-3211) : Less than 3 seconds.1.22 Scanner Unit 1) Dimension : Height 411 xSwing circle 1220 (mm) MA-3204, JMA-3210) Height 518xSwing circle 1390 (mm) (MA-3211-4) Height 518xSwing circle 1940 (mm) (MA-3211-6) 2) Weight : Approx. 24 kg (MA-3204, JMA-3210) ‘Approx. 42 kg JMA-3211-4) Approx. 44 kg JMA-3211-6) 3). Polarization : Horizontal 4) Beamwidth : Horizontal 2.4° Vertical 30° (MA-3204, JMA-3210) Horizontal 1.9° Vertical 25° QMA-3211-4) Horizontal 1.2° Vertical 25° GMA-3211-6) 5) Side Lobe Level + (within 10° of main beam) Less than ~23 dB MA-3204, JMA-3210) —23 4B OMA-3211-4) —26 dB OMA-3211-6) (outside +10° of main beam) Less than -26 dB UMA-3204, JMA-3210) 30 dB OMA-3211-4, JMA-3211-6) 6) Rotation Speed : Approx. 24 rpm 7) Wind Velocity + Relative wind 36 m/s (70 knots) (MA-3204, JMA-3210) 51.5 m/s (100 knots) (JMA-3211-4/6) 8) Transmitting Frequency: 9410 +30 MHz 9) Peak Output Power :4 kW (MA-3204) 10 kW QMA-3210, JMA-3211-4/6) 10) Transmitting Tube : Magnetron (MSF1421B ... JMA-3204) (MSF1425B ... JMA-3210) (9M61 ... JMA-3211-4/6) 11) Pulse Length/Pulse : JMA-3204] Repetition Frequency 0.08 4s/2000 Hz 0.25 nm to 1.5 nm 0.25 4s/1500 Hz 3 nm, 6 nm 0.7 ws! 750 Hz 12 nm, 24 nm 0.7 psi 500 Hz 48 nm After changing the Pulse change-over to Long. 0.25 ws/1500 Hz 1.5 nm 0.7 ws! 750 Hz 3nm, 6 am UMA-3210] 0.08 yxs/2000 Hz 0.25 nm to 1.5 nm 0.25 48/1500 Hz 3 nm, 6 nm 0.7 gs/ 750Hz 12 nm, 24 nm 0.7 ws! 500Hz 48 nm, 72 nm After changing the Pulse change-over to Long. 0.25 ws/1500 Hz 1.5 nm 0.7 ws! 750H2z 3nm, 6 nm 7 UMA-3211-4/6] 0.08 8/2000 Hz 0.25 nm to 1.5 nm 0.4 48/1500 Hz 3.nm, 6 nm12) 13) 14) 15) 16) » 2) 3) 4) 5) 6 oO) 8) 9» 10) 1) 12) 13) 14) Modulator Duplexer Radar Front End IF Amplifier Overall Noise Figure Display Unit Dimension Construction Weight Display Tube Range Scales Range Rings interval Range Accuracy Variable Range Marker (VRM-1, 2) Variable Range Marker Accuracy Bearing Scale Bearing Accuracy Ship's Heading Marker Tuning Electronic Bearing Line (EBL-1, 2) The Controls 0.8 ws/ 750 Hz 12 nm, 24 nm 1.2 us! 500H2 48 nm, 72 nm After changing the Pulse change-over to Long. 0.4 ws/1500 Hz 1.5 nm 0.8 ws! 750Hz 3nm, 6 nm 1.2 ms/ 500 Hz 12 nm, 24 nm ‘lid state modulator : MIC (Microwave Integrated Circuit) Intermediate Frequency (IF) 60 MHz Bandwidth 15 MHz/3 MHz Characteristic Linear : Less than 6 dB : Width 398xDepth 510xHeight 390 (mm) (with Handles and Sunshield) : Table top type, drip-proof (may also be mounted overhead or bulkhead) : Approx. 18 kg. : High resolution 12” monochrome CRT (Green) ke os fom ]is [3 [6 [12] 24] a] 2 0.125 | 0.25 [25 [o2 fos] 1 | 2] 4] s |i For JMA-3204, Max. Range scale is 48 nm. : Within 1.5% of the maximum of the range scale in use or 70 m, whichever is the greater. 00.00 nm to 63.40 nm (00.00 km to 117.4 km), 4 digits digital display (MA-3204) 00.00 nm to 95.10 nm (00.00 km to 176.1 km), 4 digits digital display GMA-3210, JMA-3211-4/6) : Within 1.5% of the maximum of the range scale in use or 70 m, whichever is the greater. : Fixed 360° in 1° scale Within 1° (with on the screen indicator) + 000.0° to 359.9°, 4 digits digital display STAND-BY Switch— | Operation Switches TRANSMITTING Switch— RANGE SCALE DOWN Switch— (—) RANGE SCALE UP Switeh— eeTUNING Control—“TUNE" GAIN Control—"GAIN” a “SEA” SEA CLUTTER Control—"o, BeEBR “RAIN” RAIN CLUTTER Control— ‘crip Variable Range Marker (VRM) Selection Switch— fase} No.1 VRM —ON/OFF Switch— No.2 VRM —ON/OFF Switch— Electronic Bearing Line (EBL) Selection Switch— fax} No.1 EBL —ON/O! No.2 EBL —ON/OFF Switch— F Switch— Range Rings Switch. Ship's Heading Marker (SHM) OFF Switch—(#e) Pulse Length Selection Switch— Interference Rejection Switch— Target Expansion Switch— (ar) CRT Brilliance Switch— Panel Illumination Switch— LLITD ON/OFF-Selection Switch- Waypoint ON/OFF Switch— {w) Bearing Display Mode Selection Switch—(@) Plot Mode Switch— | Plot Plot Clear Switch sa) Function Alarm ON/OFF Switch— | Alarm Alarm IN/OUT Switch— Function Off-Center Switch— (Qj)71 Cursor ON/OFF Switch— Move Switches (A), 9), (J, (¥) Touch Keys are tactile membrane with feedback to pro- duce an audible “beep” when key is pressed. 1.24 Rectifier Unit (NBA-797) 1) Dimension : Width 270xDepth 175xHeight 430 (mm) 2) Construction : Drip-proof bulkhead-mount type 3) Weight Approx. 18 kg 4) Input + AC100/110/115 V +15%, 50/60 Hz, 16 AC200/220/230 V +15%, 50/60 Hz, 1p 5) Output :DC26 V nA 1.25 Cable Length Limits between Units JMA-3204, JMA-3210 (JMA-3211-4/6 Maximum Standard Maximum Standard Scanner unit to Display unit 30m 10m 30m 15m Display unit to Rectifier unit 10m Sm 10m 5m * Maximum cable length given must be maintained for normal radar performance. IE 1.26 Options North Stabilizing Kit (NSK) : NCT-27 Note: NCT-22 CX/ST NSK unit is available to these radars. FIG. 1.1 NKE-1022/NKE-1023 SCANNER UNIT 1-6FIG. 1.2 NKE-1004-4 SCANNER UNIT FIG. 1.3 NKE-1004-6 SCANNER UNITFIG. 1.4 NCD-1323 DISPLAY UNIT FIG. 1.5 NBA.797 RECTIFIER UNITSECTION 2 OPERATION 2.1 OPERATION ‘Normally, all operations are performed from the front panel of the Display unit. The operation is simple, however, it is necessary to fully understand the functions of each con- trols in order to obtain the best picture on the CRT and maintain the radar in its optimum condition at all times. 2.11.1 The Controls The controls are shown in FIG. 2.1. % The computer will make a confirmation by a short buzzer sound and the founction display mark will be displayed within the screen, or the panel or the picture will be changed. * In the case of operation function by continuous pressing of the panel switches, the func- tion operation will be made after the long buzzer sounds. In the case of a condition that the function operation is impossible, a short buzzer will sound continuously for 3 times and an alarm will be set-off. + When the CRT brilliance and panel illumination become maximum, a long buzzer sound can be heard. When the radar is stopped and the power supply is cut-off, it will maintain the conditions of each functions before it was stopped by the memory back-up battery. * When a character “LOW BATT” is displayed, it will be necessary to replace the battery as it has already been discharged. Please use ER3 (3.6 V, 750 mAH). After replacing the battery, “LOW BATT” will be displayed at its first time of setting the power supply to ON. Perform the following operation (initialize). This display will not appear from the second time of operation. @ Wait until the “ST-BY” appears. @ When the “Interference Rejection” switch is continuously pressed, a buzzer sound of “p.p.p-p—" can be heard. Please repeat this procedure for over 2 times. @ Press the "X-MIT” and “ST-BY” switches simultaneously, and stop the radar. Above procedure is the initialization. After the time as elapsed for more than 5 seconds, put the power supply to ON in accordance with the “2.1.3 Operation Procedure”, and after the power supply is put to ON, the radar will be in the following condition. Range: 3NM HIN/C Bearing: H Pulse Width: Short pulse: IL/ Electronic Cursor, Variable Range Marker, Target Expansion, Radar Interference Re- jection, Alarm, Plot, Off Centering, Way Point, Own Ship's Position; “OFF”. Image Brilliance, Panel Illumination: Medium Brilliance.21.2 Function of Controls @ [SEBY), XMIT] switches a. In the stop condition, the ra not operate as the power supply will not be sup- plied to the Display unit and the Scanner unit. Therefore, no images will be displayed on the screen. Note: Even when the radar is in the “OFF” condition, the bower is supplied to a part of the power supply circuit inside the Display unit and the Scanner drive motor cir- cuit. When a rectifier unit is used, please note that there will be an output at the output terminals of TB701-1,2 of the rectifier unit. ». By pressing the (5374) "switch, the power supply will be supplied to the Display unit and the Scanner unit. However, under this condition, the modulator circuit inside the ‘Scanner unit and the drive motor will not ‘operate. All other circuits will operate. The PPI images will not be displayed. Approximately 90 seconds in the case of JMA-3204 and. |JMA-3210 and approximately 3 minutes after pressing the (®") switch, the character “ST-BY” will be displayed at the left-bottom of the screen which will indicate that the transmitting preparation has been completed. Note: During the time that this ‘switch is pressed, the modulator high voltage ower supply and the CRT high voltage power supply are supplied. Also, even before the character “ST-BY” is «a at the left-bottom of the screen, the scanner will start to rotate when the switch is pressed. ¢. By pressing the (23°) switch, all circuits of the radar will operate and will start the transmitting. At this time, if the Scanner unit safety switch is sett the Scanner will_start its rotation and the images will be displayed on the screen. When the switch is pressed in the condition that the safety switch is set to [OFF], there Will be no display of PPI images on the screen. It will be in its normal operation Note: J. With the scanner in rotation the PPI images will be displayed from the time the bearing re-set signal (62) is received from the Scanner unit. (Please note, that there may be an approximately 3 seconds at the most for the waiting time) 2. When performing the radar observation in a short periodical intervals, it is recommended to press the switch and press the switch when making an observation only. By this method of observation, a Tonger life of the magnetron can be maintained. d. When stopping the operation of the radar, press both the and switches simultaneously for approximately 0.5 seconds. By this opeFation, it is-passi- ble to stop the radar operation. It is possible to confirm the stop condition of the radar by observing that no images (characters or PPI images) appear on the screen. ¢€. If the ship’s mains is supplied to the radar even in the “OFF” condition of the radar, the switch will be illuminated by a weak light. @ [Range Sele] Scate down (a) , Scale up (BE) switches By these switches, the range on the screen can be changed and also the pulse repeti- tion frequency, pulse width and range scale intervals are changed simultaneously. The Tange scale is displayed at the left-upper portion of the screen and the range scale intervals is displayed right below the range scale. When the power supply is set to “ON”, it will be in the settings which the radar was operated in the previous condition.(arit wa previously operated in the 12 NM range, it will be in the 12 NM range. The ange is set to 3 NM range when shipped from the factory). The relation among the range scales and range rings, pulse repetition frequency, transmitting pulse width are shown in the following TABLES 2.1~2.3. TABLE 2.1 JMA-3204 Range | Interval of | No. of | Pulse Repetition | Transmitting Bandwidth of Scale_| Range Rings | Rings Frequency Pulse Width IF Amplifier 0.25n.m[ 0.25 nm. 2 2000 Hz 0.08 15) 15 MHz 0.5 nm] 0.25 nm 2 2000 He 0.08 ns 15 MHz 075mm] 0.25 mm. 3 2000 Hz 0.08 4s, 15 MHz 15 am| 0.25 nm 6 2000 He 0.08 ps 15. MHz 3 nm[ 05 am é 1500 He 0.25 ps 3MHz 6 om{ 1 am 6 1500 He 0.25 us, ‘MHz 12 am| 2 nm 6 750 He 07 us ‘3MHz 24 nm] 4am. é 750 He O7 ps 3MHz om) 8 nm 6 500 He 07 us 3MHz TABLE 22 JMA-3210 Range [Interval of | No. of | Pulse Repetition | Transmitting Bandwidth of Scale_| Range Rings | Rings Frequency Pulse Width IF Amplifier 0.25 nm] _0.125am. 2 2000 Hz 0.08 ps 15 MHz 05 nm 0.25 am. 2 2000 Hz 0.08 ps 15 MHz O75 nm.) 0.25 nm. 3 2000 Ha 0.08 us 15 MHz 15 _am| 025 nm. 6 2000 Hz 0.08 us 15 MHz 3 nm] 05 am. 6 1500 Hz 0.25 4s ‘3MHe 6 am] 1 am 6 1500 Hz 0.25 us ‘3MH2 12 nm| 2 nm. 6 750 He O7 ps 3MHz 26 nm) 4am. 6 750 Ha 07 us 3MHz 43 nm] 8 nm. 6 500 Hz 07 ms 3MHz 72 nm] 12 am 6 500 Hz 07 ns ‘3M| | TABLE 23 JMA-3211-4/6 Range | Interval of | No. of | Pulse Repetition | Trancmitting Bandwidth of Scale_| Range Rings | Rings Frequency Pulse Width IF Amplifier 0.25 a.m) 0.125 nm 2 2000 Hz 0.08 us 15. Miz 05 nm] 025 am | 2 | 2000Hr 0.08 us 15 MHz O75nm.{ 0.25 nm. 3 2000 He 0.08 us 15 MH (15 mm 025 nm 6 2000 He 0.08 ps 15 MHz 3am 05 nm. 6 1500 He 04 us SMH 6 am! 1 am. 6 1500 He 04 Hs 3M 2 am] 2 nm 6 750 He 08 us ‘3.MHz 24 am) 4 am. 6 750 He 08 ps 3Mu | 4¢ am] 8 am 6 500 He 12 as 3MHe 72 nm] 2 nm | 6 500 He 12 us 3M TUNING |Control By this Control, the varactor voltage of the local oscillator of the receiver unit is varied and its oscillation frequency is changed. Locate a suitable target and adjust this control so that the target can be clearly observed on the screen. When there is no target, adjust this control so that the Tuning indicator which is displayed at the leit- bottom of the screen will be the longest. This adjustment should be performed by using the range of more than 3 NM after approximately 10 minutes has elapsed from the start of transmitting. Please obtain the best tuning condition by observing the image. Note: The change of length of the Tuning indicator mark has no direct relation with the life of magnetron and output power. GAIN] Control By turning this Control to the right, it increases the gain of the Receiver and increases the range which the targets can be observed. This control shall be adjusted so that the most suitable images are obtain according to the range in image. In the short range the gain is lowered and in the long range it is adjusted so that some receiver noise appears on the screen. SEA CLUTTER] Controt Even in the calm sea there is sea-clutter from the nearby sea-surface and as the sea becomes rough the images of this sea-clutter strongly appears on the screen. Therefore, this control is used to reduce the images of the sea-clutter by decreasing the receiver gain in the short range. By turning this control to the right, the effective- ness of the sea-clutter suppression is increased, however, it is necessary to perform this adjustment carefully in order to avoid losing of important targets. When the sea is calm and no images of sea-clutter appear near the center of the screen, then turn this control to fully counter clockwise.@© [RAIN CLUTTER] Contro! ‘There is times that the images of rain or snow appear on the screen and becomes difficult to separate the images of targets. Under these circumstances it is necessary to turn the [RAIN-CLUTTER] control to clockwise direction so that an outline of the target will appear on the screen. In the short range, it will be more effective if both the [GAIN] control and the [RAIN-CLUTTER] control are used together. When there is no affect from rain or snow, this control is turned to fully counter clockwise in order to prevent losing of small targets. @ [YRM) Controt This control is used to adjust the increase/decrease of the range of the Variable Range Marker (VRM). When turned to the right, the range is increased and when turned to the left, the range is decreased. When the range in usage reaches the maximum value by increasing its value or when the value becomes zero by decreasing its value, a buzzer will sound and the operation will be stopped. The variable range marker which is controlled is displayed inside [] by inverse charac- ter located at the right side of the character “VRM"” at the right-top of screen, No.1 is VRM [1] and No.2 is VRM These VRM's are selected by the VRM SELECT] switch. When making the settings of alarm range, these VRM's are also used as explained in a. VRM SELECT] Switch 9} ‘This switch is used to select the variable range marker which is desired to control the increase/decrease of the range. The number (“1” or “2”) of the variable range marker which has been selected will be displayed at the right side of “VRM” at the right-top of the screen and becomes “VRM 1” and “VRM 2”, ‘The marker which is displayed at the numeric side can be moved/operated. When this switch is pressed each time, it will change from “1” to “2” and vise-versa. @ [No.1 VRM ON/OFF] Switch This switch is used to set the ON/OFF of the No. 1 VRM (VRM{i]) which is display- ed on the screen. The No. 1 VRM is displayed on the screen as dash line, and the range is displayed after the VRM [1] on first line at the upper-right of the screen. The marker, numeric can be set to ON-OFF simultaneously. @ [No.2 VRM ON/OFF] Switch ‘This switch is used to set the ON/OFF of the No. 2 VRM (RM {2]) which is display- ed on the screen. The No. 2 VRM is displayed on the screen as dotted line, and the range is displayed after the VRM [2] on the 2nd line at the upper-right of the screen. The marker, numeric can be set to ON-OFF simultaneously. ® [Blectronic Bearing Line] (EBL) Control This control is ysed when taking the bearing by rotating the Electronic Bearing Line (EBL) to the right and left. When this control is turned in clockwise direction the EBL will also move in clockwise direction, and when turned in the counter clockwise direc- tion, the EBL will also move in the counter clockwise direction, ‘The Electronic Bearing line which can be controlled is displayed inside the [) at the right side of the character EBL on the right-top of screen, 2-5@ [EBLSELECT] switch 9) This switch is used to select the electronic bearing line which is desired to control the | bearing. The number ( of the Electronic Bearing Line which has been selected is displayed on the right side of [EBL] at the right-top of screen in inverse characters, and will be the “EBL [1] or EBL [2].” No. VRM Wil change to “T” in True Bearing display with True Bearing unt attached, @ No. 2 EBL TRUE/RELATIVE BEARING SELECT. }) which is displayed on the screen. The number 1 EBL is displayed on the screen as a dash line, and the bearing angle of the electronic line is displayed after the EBL [1] or the 3rd line at the upper-right of the screen. This switch is used also for simultaneous ON-OFF of EBL and numerics. When a Gyro (with true bearing unit), Loran C or Magnetic Sensor is connected, it possible to change the display of the bearing angle from relative bearing to true bear- ing or vise-versa by pressing the [1 ON/OFF ] switch continuously for approximately 2-3 seconds. Following the numerical display, if itis relative bearing it will be display- ed as R and if it is ture bearing it will be displayed as T. For example, the EBL [1] 193.5R. Even if the relative bearing and true bearing is switched over, the position of EBL within the screen will be fixed 2-6No. 2 EBL ON Switch) This switch is USed to set the ON-OFF of the No. 2 BBL (EBL [2]) which is displayed on the screen. The No. 2 EBL is displayed on the screen as dotted line, and the bearing angle of the cursor is displayed after the EBL [2] at the upper-right of the screen (4th 1e). When a Gyro (with true bearing unit), Loran C or Magnetic Sensor is connected, it is Possible to change the display of the bearing angle from relative bearing to true bear- ing or vise-versa by pressing the [2 ON/OFF] switch continuously for approximately 2-3 seconds. Following the numerical display, if itis relative bearing it will be display- ed as R and if itis true bearing it will be displayed as T. For example, EBL (2] 058.0T. Even if the relative bearing and true bearing is switched-over the position of the EBL within the screen will be fixed. "F] Switch (No. 2 EBL TRUE/RELATIVE BEARING SELECT] Range Rings ON/OFF] switch ©) This switch is used to set the ON/OFF of the display of the range rings. When this ‘switch is pressed each time, it repeats the ON and OFF operation. ‘Ship's Heading Marker OFF] Switch (sw) During the time that this switch is pressed, the Ship’s Heading Marker (SHM) will disappear from the screen and if this switch is released, the SHM will be displayed on the screen. This switch is used when the SHM and images are overlapped and difficult for the observation. After this switch is released the display will disappear for about 1-3 seconds and then the display will be restored. Note: When it is in the Course Up Mode, the SHM will disappear if this switch is press- ed until the long buzzer sound. Pulse Width Select] Switch When this switch is pressed, the transmitting pulse width will change as per Table below in the 1.5~6 NM or 1.5~24 NM ranges. When the weather is fine, small targets can be enlarged and displayed by using longer pulse width for easier observa- tion. When the weather is poor, it is possible to reduce the effect of rain-snow by making the observation using the normal pulse width. JMA-3204/JMA-3210 Range ‘Transmitting Pulse Width [Transmitting Repetition Frequency Scale (NM) | Normal Long Normal Long 15 0.08 ws 0.25 us 2000 Hz 1500 He - 0.25 ps 07 us 1500 Hz 750 He.JMA-3211-4/6 Range ‘Transmitting Pulse Width [Transmitting Repetition Frequency] Scale (NM) [7 Normal Long Normal Long 0.8 us 0.4 us 2000Hz | 1500 Hz 0.4 us 0.8 us 1500 Hz, 750 He 0.8 us 12s 750 Ha 500 Hz Interference Rejection] Switch ‘This switch is used to reject-suppress the radar interferences from radars onboard other ships or other X-band radar onboard the own ship. When this switch is set to ON ( @_ mark is displayed at the left-top of screen), some noise and almost all of radar interferences will be rejected. However, it is neces. sary to be very careful that you do not lose weak signals which barely appear on the radar screen. Therefore, due to this matter it will be better to have this switch set to OFF if there is no problem in the observation even when the radar interferences are displayed. (The display mark will disappear) ] move the (+) mark to a position where it is desired to have the own ship position The (+) mark can only be moved within the 1/3 radius. After overlying this (+) mark on the desired position, press again the “OFF CENTER" switch. The own ship position will be moved. At lower-bottom part of screen, [OFC] will be displayed. If this switch is pressed again, it will return back to the center of screen. Only when (+) mark is appearing, it is possible to move to the (+) mark position. When the (+) mark is not appearing, it performs the OFF-SET operation. Move] Switches [A] [¥] =] DP] ‘These switches are used for moving the mark (+) when it is in the OFF CENTER mode or moving the cursor mark (+) in the case of cursor mode. ‘The mark will move in the pointing direction & symbol Note: These switches can not be pressed simultaneously. If these switches are pressed simultaneously, it can not be guaranteed that the function of the switch will be the same as indicated. So be careful! (CURSOR ON/OFF) and (P-MODE SELECT) Switches FF It is possible to read-off the bearing and range of the center of cursor mark (+). This switch is used for ON/OFF of cursor mark (+) and change-over of the P Mode (move mode of EBL (bearing cursor) and VRM (variable range marker)) by the MOVE switch as specified in @ above. Thus, this switch is used to segregate the usage of above 2 functions. @ CURSOR ON/OFF) Switch Wi this switch is pressed, the [C] mark at the upper-right of screen and the cursor mark (+) within the screen will be layed. The bearing and range of the center of cursor mark can be read. Read the position of EBL [2] for bearing and VRM [2] for range. When the cursor mark is used, it will be impossible to use No. 2 EBL and No. 2 ‘RM. The cursor mark can be moved to any position within the screen. ‘This mark is fixed within the screen, even when the range has been changed or when the center move operation has been performed. However, together with these operations, the values showing the position of markers will be changed. When this switch is pressed again, the cursor mark will disappear and No.2 EBL, No. 2 VRM will be displayed. No. 2 EBL, No. 2 VRM will not track the center of cursor mark. They are inde- pendent and will return back to the condition which the cursor mark was used before. 2-16(P-mode Setect] switch) When this switch is pressed continuously, a long (p----) sound will be made and together with this sound the [P] mark will be displayed at the upper right of screen ‘The period that the [P] is visible. The [A] [Y} switches will be changed to operate as the switches to move the variable range marker and the ) | switches will be changed as the switches to move the bearing cursor. Both the knob and switches are used for the control. The side that can be con- trolled is the side selected by the SELECT switch, If this switch is pressed again, it will return back to the cursor mark (+) display of (1) above. (2) 21.3 Operating Procedure After fully understanding the functions of the switches and controls on the front panel of the Display Unit, start the operation of the radar according to following procedure. —Start— () Press the of power supply switch and after waiting for approximately 10 seconds, confirm that the bearing scale which shows the image range is displayed on the screen. (2) After approximately 90 seconds for JMA-3204/3210 and approximately 3 minutes for JMA-3211-4/6, a buzzer will be sounded and after the display at the lower-left of screen is changed to “ST-BY", press the switch. Then it will start the trans- mitting. At this time, the range will be the range when the radar power supply was set to OFF in its previous usage. This is performed by the data maintain (back up) function. —Observation— (2) Press the “Range” decrease (Al) or increase (IBF) switches and set to the range required for making an observation. (Range, Range Scale Intervals willbe displayed at the upper left of screen.) (2) Turn the [TUNING] control to the cw/ccw and set to a position where the targets can be most clearly observed. When there is no suitable target, make adjustment of the Tuning Indicator displayed at the lower left of screen so that the indicator will be the longest. (There is a maximum of 8 square boxes O. After approximately 10 minutes has elapsed, make this adjustment again. (3) Make adjustment of the [GAIN] control so that the targets are most clearly displayed for observation. Also, if necessary, make adjustment of the [SEA-CLUTTER ] control and [RAIN-CLUTTER control. Further, make adjustment of the switch for adequate brilliance for easy observation. (4) For the measurement of the range of target, use the fixed range marker or variable range marker (VRM) and for the bearing, use the electronic cursor (EBL).—Stop— Press both power supply switches ind simultaneously and confirm that there is no display left on the screen, At this time, if it is necessary to make an observation again in a short period of time, press switch and keep the radar in “ST-BY” condition. Then it will be possible to set the radar to transmitting condition, when required, by pressing only the switch, 22 MEASUREMENT On the Screen of the Display unit, the position of other targets (the range from own ship and the bearing angle of own ship's heading as 0°) with the position (precisely the position of the Scanner unit) of own ship as an original point of co-ordinates can be display- ed on the screen as polar co-ordinates (PPI display). That is. it is like looking around with the position of own ship as the center of the screen, and the targets are displayed as bright images. 22.1 Range Measurement (1) The range measurement of the target is made by pressing the switch after confirming the image of the targets on the screen and the measurement is judged by the position of the image where it appears on the scale using the fixed range marker. (2) Either one of the No.1 or No.2 variable range marker (VRM) is selected by pressing the fem} switch. Then turn the “Variable Range Marker” control so that the marker i will overlie on the image. The range up to the target from the own ship will be display- ‘ed at the right-top of the screen after the character “VRM” O. 6 Measured Range by No. 2 VRM I 6M, { Read as 53 NM: 1 51M 479 NM(3) When making the measurement by using the cursor mark (+), press the cursor mark (+) switch and make the [C] mark to appear at the upper right of screen. Press the cursor mark move switches, >) (A) [V| . and overiay the center of cursor mark over the image which is required to measured. (Refer to figure below) Note: When more than 2 move switches are pressed simultaneously, an accurate move- ment can not be obtained. It is necessary to press the move switch 1 by 1 and perform the overlay of position. nuP GSS 3 al Range and Bearing Measured by Cursor Mark (+) Example of Display when the cursor mark is used for the display. 222 Bearing Measurement There are 3 kinds of bearings of the target, that is, H bearing (HUP) (Relative), N bearing (NUP) (True) and C bearing (CUP) (Course). However, this radar normally displays the relative bearing mode. (1) The H bearing (Relative) is the bearing which the ship’s heading direction of the own ship is fixed to 0 degree. First, either one of the No.1 or No.2 “Electronic Bearing Line” (EBL) is selected by pressing the switch. Then turn the EBL knob so that the marker will over lay on the image, and the bearing of the target will be displayed at the upper-right of the screen after the character “EBL” in 4 digits. (Refer to FIG. 2.2.). For details, refer to paragraph 2.1.2. @.——— VRM: 2 Numerical Date EBL: Cl) Numerical Data Ship's Heading Marker eet Image of Target to be Measured i vem OD) i FIG. 22 MEASUREMENT OF TARGETS2.3 USING THE CONTROLS When measuring the position of the target on the radar screen, the best picture on the screen allow the accurate measurement. Controls to get the best picture on the screen are as follows. “TUNE”, “GAIN”, “SEA CLUTTER”, “RAIN CLUTTER” Understand fully their functions described in 2.1.2.. before using these controls. In manipulating, pay attention particularly to the following points. Q) EEONING Jcontrot If the best tuning condition is not obtained, especially the target at the long range and even the small target at the short range may be missed. Adjust this control so that the clearest and the strongest echoes may be displayed on the screen. However, the tuning condition is also possible to confirm by the tuning indicator at the left-bottom of the screen. Radar magnetrons and MICs, during their aging process, may take several minutes to completely stabilize on frequency. So, after switching to ON and tuning initially, the tuning should be rechecked after the first 10 minutes: (2) [GAIN] contro ‘The correct setting of the GAIN control is for light background speckle to be just visible on the screen, The equipment is then in its most sensitive condition. Objects will be detected at the greatest possible range. With too little gain, weak targets may be missed and not displayed. In addition, there may be a decrease in detection range. With excessive gain, the difference between echoes and background noise contrast will be substantially reduced, making target observation more difficult. In areas around strong targets (buildings, hills, towers, etc.), the gain might be tem- porarily reduced to clarify the picture. This should be done with care so important targets will not be missed. With the gain at its normal setting, clutter from rain or snow may obscure the echo from a ship or other objects inside a squall or storm. A temporary reduction in gain along with proper RAIN CL/SEA CL settings will usually permit the stronger and more distinct echo from the ship or other objects to be dis- tinguished. Detection of targets beyond the storm may, however, require slightly higher gain than normal, since the storm may attenuate the echoes from the targets severely. The GAIN control should always be reset to the optimum level following the range scale changes. In addition, when environmental conditions change, readjustment of the gain may be required. (3) [SEA CLUTTER] contro! Whereas the [GAIN] control affects the strength of echo returns at all ranges, the effect of the [SEA CLUTTER] control is greatest on nearby returns, becoming prog- ressively less as range increases. The bright section on the screen due to the sea clutter disappears gradually as the SEA CLUTTER] control is turned CW.mT 24 (4) ‘The [SEA CLUTTER] control reduces the strength of the mass of random signals re- ceived from waves at short range. The STC level used should be sufficient to reduce the strength of sea clutter while still allowing small nearby targets to be distinguished. The level should never be set so high as to blank out all nearby returns. With the excessive Sea clutter suppression, the important targets disappear too. The targets, such as buoy, small craft, etc., can be observed only in the calm sea and in the short range often disappear together with the strong sea clutter as the [SEA CLUTTER] control is turned CW. The [SEA CLUTTER] control may be useful to reduce effects from rain or snow clut- ter in the immediate vicinity of the vessel. A temporary increase in the setting may permit stronger echoes from ships, and some navigational marks inside storms or squalls, to be distinguished. ‘At close range in crowded regions the control may be temporarily advanced to clear the picture. This should be done with care, so as to avoid missing important target returns. ‘The [SEA CLUTTER] contro! should always be checked and reset to the minimum required level after any temporary alteration or when environmental conditions have improved. It is important to remember that both GAIN and SEA CLUTTER levels should be checked and adjusted each time a new range scale is selected. This is important to assure that excessive sea clutter or insufficient gain will not cause important targets to be missed or not displayed. [RAIN CLUTTER] controt The [RAIN CLUTTER] control enables to discriminate adjacent targets. In the heavy rain or snow, this control allows to give clear images. Also, this control can reduce the sea clutter. Therefore, use of both [SEA CLUTTER] and [RAIN CLUTTER] will help to make the images clear. But with excessive rain clutter suppression, the small target and the targets at the long range are difficult to be seen and disappear. Take notice of this fact. Usually, set this control to fully CCW. READING THE SCREEN ‘The most important problem for a radar user is to interpret the radar screen data correctly and to help the ship to proceed along its course. It is necessary to fully under- stand the radar before putting to operation it. On a fair day, watch a target without any aids and then see its echo on the screen and compare. This kind of practice and experience is indispensable. Main usage of a radar include monitoring the course of own ship as well as other ships in the open sea; checking the presence of buoys, etc. Radar is widely used when entering a port, when coasting and determining own ship's position on the chart by taking into consid- eration the distance and bearing of land, islands, etc., and also to ascertain the position and movement of a heavy rain. a ‘The following are some of important facts to know about the radar screen. Radar Horizon . ‘To some extent, the radar waves propagate along the earth’s curvature, through layers of air in the region which the waves are propagated. If the waves are prop- agated under normal conditions, their distance (D) from the horizon is said to be about 10% longer than the optical horizon. This is given by the following relation: 23 VR + V2) (nm)