the 2nd key and then press the "7" key. The paper speed will im- To turn this feature on, simply press the 2nd key, then press the "4" key. The paper speed will immediately slowdown, signifying that the function is enabled. To turn the Alternate Transmit and Print feature off, simply press mediately speed up, signifying that the function has been turned oft. When entering any number or combination of keys on the keyboard and you make a mistake, press the 2nd KEY then 0. This will clear the keyboard. For example, if you wanted to set a Lower Limit of 50 feet and pressed 40 feet instead, beforepressing the Lower Limit Key press 2nd - 0 and the keyboard will be cleared. You could then press 5 - 0 - Lower Limit for the desired range. To cause the X-15Ato reprint the level of Disbrimination, SCC, or Pulse Width at the bottom of the page, simply press2nd and then the corresponding key (DISC, 5CC/MARK,or PULSE) and it will be reprinted immediately. INSTALLATION AND OPERATION MANUAL X-15A COMPUTER SONAR Paper Saving Feature Without Alternate Transmit and Print Minimum Maximum Paper Speed LOWER Paper Speed I APPROXIMATE PAPER SPEED LIMIT RANGE (feet) 10-120 130-510 Inches Per Mm 1.0 0.5 Hours Per Roll 10 520-830 Below 840 0.15 0.15 20 66 66 -- Inches Per Mm 2.35 1.4 0.75 0.75 Hours Per Roll 4.25 7.14 13.3 13.3 LOWER LIMIT RANGE (feet) 10-120 With Alternate Transmit and Print Minimum Maximum Paper Speed Paper Speed Inches Per Mm 0.5 0.20 0.15 0.15 Hours APPROXIMATE PAPER SPEED Per Roll 20 50 66 66 Inches Per Mm 1.4 130-510 520-830 Below 840 LITHO USA 0.8 0.75 0.75 Hours Per Roll 7.14 12.5 13.3 13.3 988-0096-01 ·LOWRANCE ELECTRONICS, INC. 12000 F, SKELLY DR, TULSA, OK 74128 PDF compression, OCR, web-optimization with CVISION's PdfCompressor INDEX Specifications Service Information Introduction Installation How It Works Transducer Selection Basic Operation Suppressor Paper Speed GRAYLINE® Range Lower Limit Upper Limit Lines Marker Scale . 1 1 2 2 3 4 4 5 6 7 7 8 9 9 level whereas the highest value (4) is the strongestlevel and should be used only when severe noise is present. To use the Discrimination function, simply press the level of noise rejection desired, from 1 to 4, then press the DISC (Discrimination) Key. There should be an immediate change in the amount of noise presenton the paper. The Discrimination setting is printed at the bottom of the paper each time the level is entered and at intervals thereafter. The Discrimination -function can be disabled at any time by pressing 0 - DISC. Example: Enter a Discrimination level of 2. Press: 2 - DISC Result: 2----- 2'I- 9 10 10 10 11 --· - -- 2 -··---- ______ End Of Paper Zero Adjust How To Read Graphs Paper Loading Stylus Replacement Stylus Belt Replacement Do's and Dont's Troubleshooting Advanced Operation SurfaceClarity Control (SCC) Feet, Fathoms, Meters Transmitter Pulse Width Discrimination Transmit and Print Alternate ..14 .15 .16 Figure 40 Transmit and Print Alternate When using the X-15A in deep water, or if you wish to simply conserve paper, it may be desirable to slow the paper speed even more than the automatic system allows. However, when doing so, you may get "over print' or very dark, heavy printing over an area that is difficult to read. Much detail can also be lost due to this. A feature that is available on the X-15A is the Transmit and .16 17 17 18 18 Print Alternate function which, when activated, causesthe stylus to print every other revolution instead of every revolution. This accomplishes four things: 1. Since the stylus only prints every other revolution, the recorded information doesn't have the "over printt' problem, therefore good records are attainable at slower paper speeds. Also, the scale numbers are spread out more, making them more legible. 2. Reduces the possibility of "wrap-around". This is the undesirable occurrence of the second or third bottom echo printed on the paperat the top or middle of the page. Many times this can interfere with fish or other targets that you wish to see. 3. Reduces the reverberation effect. This happens mainly on lower frequency units, but it can happen on higher frequency models. Reverberation is heavy, scattered noise marks caused by the transmitted signal becoming trapped between the surface and the bottom, usually scattered in heavy plankton layers or baitfish schools. This causesa great many lines to be printed on the page. By enabling the Transmit and Print function, the transmitter is triggered only half as many times as normal, putting less energy into the water (same amount of power, just not as often) which reduces the amount of noise seen. 20 21 4. Slows the paper speed. A significantamountof paper can be saved by using the Alternate Transmit and Print feature. 21 PDF compression, OCR, web-optimization with CVISION's PdfCompressor resolution. For example, if a 50 ps initial transmitter pulse length is selected, and the Suppressor control is rotated to maximum, the transmitter pulse length would be 850 ps. Returning the Suppressor control to minimum will restore the unit to a 50 ps transmitter pulse length. The X-15A will display the initial transmitter pulse length at the bottom of the paper when you override the micro-computer. To distinguish the initial transmitter pulse from the other information printed on the paper, the graph will print P-100 (if the pulse is set to 100 micro-seconds.) A 50 us initial pulse length would be displayed as P-SO. To set the initial transmitter pulse length, simply press on the keyboard the initial pulse length desired and then press the PULSE key. For example, to set the initial transmitpulse length to 150 micro-seconds, press 1 - 5 - 0 - PULSE. This will override the micro-computer's selection and set the initial transmitter pulse length to 150 micro-seconds. P-iSO will be printed at the bottom of the paper to signify that the entry has been confirmed. (Note: When an initial transmitpulse length is set, this length will be fixed for all depth settings until changed.) To return control back to the micro-computer, press 0 - PULSE and the micro-computer will select the initial pulse length. Example: Set the initial transmit pulse length to 100 micro-seconds. Press: 1 - 0 - 0 - PULSE Result: -- Ia----- --·---··---------- --. 2L1-------.--- 29---- ------bO----F-ILU -·----- Figure 39 Discrimination Noise pulses are the largest complaint most often received about sonar units. Lowrance has had the patented Suppression systemfor many years which is quite effective at eliminating noise from the display. (See Transmit Pulse Width.)The only drawback to the Suppression system is that it increases the transmitter's pulse length which decreases resolution and causestargetsthat are close together to merge into one "blob" instead of two distinct images. Discrimination is a program installed in the X-15A's micro-processor that enables it to process the output from the receiver, determine which signals are noise and eliminate them, then print only the legitimate echoes. Using this concept, the transmitted pulse does not have to be increased, therefore records with high resolution and high noise immunity can be achieved. (The Suppressor Control may be used with the Discrimination to cancel OUT heavy interference or noise whenever high resolution is not required.) There are four levels of Discrimination that can be used. The lowest value (1) is the weakest If you have a problem with your sonar unit, please give us a chance to help before sending it in for repair. Assistance can often be extended by telephone or letter. Write or call one of our Authorized Service Centers or the Lowrance Electronics, Inc., Customer Service Department in Tulsa, OK. (Toil-free1-800-331-3889). Please detail the problem you power. Power: are experiencing. Our Service DeOutput 1600 watts typical peak-to-peak. partment may be able to save you the inconvenience of returning (200 watts RMS) Weight: your unit. If it is determined that your unit 8.5 lb. (3.9 Kg) Dimension: must be returned, full shipping inWith Gimbal Mount: structions will be provided. Width - 12¼" SCHEMATIC DIAGRAM AND Height - 9" PARTS LIST Depth - 6%" Should you desire a Schematic Instrument Only: Diagram and Parts list for your Width - 101/4" Lowrance TRUELINE RECORDHeight - 8¼" - 6%" ER, send $1.00 to PARTS LIST, Depth Lowrance Electronics, Inc., 12000 East Skelly Drive, Tulsa, OklaNOTICE homa 74128. Be sure and give us Periodically wash the Transducer Face with soap and water the Model Number and Serial Number of your SONAR to removeany oil film that may collect Oil and dirt on the face INSTRUMENT SPECIFICATIONS -- X-15A Depth Ranges: Feet, fathoms, meters. Operating Frequency: 192 kHz (192,000 cycles per second); accuracy is within 0.6 percent. Pulse Length: (duration of pulse): 200-l000ps (30-2000gsprogramable) Operating Voltage: Minimum: 10 volts DC Maximum: 15 volts DC Operating Current: 0.7 to 1.8 amps depending on printing densityand output will reduce sensitivity or may even prevent sounding. GOT A PROBLEM?LET US HELP! NOTE: This sonar uses LPG -605 Chart Paper. PDF compression, 20 OCR, web-optimization with CVISION's PdfCompressor 1. INTRODUCTION The Lowrance X-15A is a highly sophisticated recording depth sounder. Thanks to a micro-computer, the X-15A can do more than any other sonar unit in its price range plus many that cost much more. Thanks to a waterproof keyboard, full control of the system is at your fingertips to meet the changing demands of varying bottom conditions, water depth, and boat speed. You can selectthe unit's sensitivity, suppression level, upper and lower depth range, paper speed, GRAYLINE, and many more features. The patented Lowrance variable suppression systemcombined with the new Discrimination feature not only filters out false signals withoutdistorting the real ones, but is synchronized with the GRAYLINE function to provide clear signals under all conditions. to move down the edge of the paperwhile the sound pulse is the Suppressor control turned down to minimum when looking pulse length remains at 600 micro-seconds. traveling through the water, and when an echo is detected, the stylus makes another mark on the paper. The depth of the object which reflected the echo can be read in feet by comparing its location on the paper to the depth scale printed on the paper. The paper speed is controlled by a variable speed motor. During one revolution of the stylus belt, a very narrow mark will be made by the flexible stylus, but the paper will move a small amount before the next revolution. Each mark will blend into the one before so that a composite "picture" of the target will be made, one tiny mark at for fish. a time. 2. HOW IT WORKS When the unit is turned on, an electronically regulated motor drives a lightweight belt located at the right edge of the recording paper. The stylus is attached to this belt. When the stylus is at the top of the paper a small mark is made. This is called the zero mark, and represents the surface of the water. The stylus continues Due to the manyfeaturesthat this unit has, this manual has the operation section split into two parts. The first section is entitled "Basic Operation" and covers everything that is absolutely necessary to use the X-1SA in a wide variety of situations. It will tell you how to use the basic controls However, it is helpful sometimes to have longer pulse width when resolution is not a concern. When using a sonar in deeper water, it is easier for the unitto detect a longer pulse coming back from the bottom or from fish. This is called "Probability of Echo Detection". The probability of the unit being able to detect an echo returning from deep water is diminished because the further the sound pulse has to travel, the weaker it becomes. By broadening the pulse length, in essence, a larger signal is transmitted and it is easier for the receiver to detect it. For this reason, the micro-computer in the X-15A automatically increases the initial pulse length of the unit as deeper lower limits are set by the operator. (Note: Initial pulse length is the pulse length of the unit when the Suppressor control is turned to minimum.) - Sensitivity, Suppression, Paper Speed, GRAYLINE, Range, plus a few special functions. This section Will be adequate for most situations. However, once you have mastered the basic operation of the X-15A, you may. wish to try some of the features described in PULLEY DRIVE Figure 1 sTYLUs DRIVE BELT STYLUS GRAPH PAPER PULLEY TRAVEL pressor control clockwise. The maximum amount of pulse length added to the initial transmitter pulse length is approximately 800 micro-seconds. In other words, if the LOWER LIMIT is set to 420 feet, and the Suppressor control is rotated to the maximum position, the transmitter pulse length would be 1220 micro-seconds. (420 initial + 800 = 1220.) Earlier, we talked ab ...