TECHNICAL MANUAL FOR COMPACT VHF DSC RM2042

RM20423 SERVICE3.1 MAINTENANCEPREVENTIVE MAINTENANCEIf the VHF DSC RM2042 has been installed in a proper way the maintenance can, dependent on theenvironments and working hours, be reduced to a performance check at the service workshop at intervals,not exceeding 12 months. A complete performance check list is enclosed in this manual, chapter 3.5PERFORMANCE CHECK.Inspection of the antenna, cables, and plugs for mechanical defects, salt deposits, corrosion, and anyforeign bodies shall be done at regular intervals not exceeding 12 months.Along with each RM2042 a test sheet is delivered in which all the measurements, made in the testdepartment of the factory, are listed. If the control measurings made in the service workshop should notshow the same values as those listed in the test sheet, the set must be adjusted as specified inchapter 3.6. ADJUSTMENT PROCEDURE.CHANGE OF BATTERY FOR BACK-UPThe RM2042 is constructed with a real time clock, which uses a lithium battery for power back-up. Bymeans of this battery, it is possible to maintain track of time and date even though the RM2042 has beenturned off.The capacitance of the battery is 180 mAh (milli Ampere hours) and as the real time clock only consumesa current of about 7µA, the battery should last for a period of at least 2.5 years. However, in practice thisperiod will be longer, because the battery is only used when the RM2042 is turned off.The battery is located at the microprocessor (module 2) and is soldered to the PCB to obtain mechanicalstability.The battery can be ordered from S.P. Radio, Denmark by using the spare part number 47.004.IMPORTEN! The old battery shall be handed over to the authorities for proper destruction, to avoiddamages of the enviromental by the lithium.CHANGE OF SOFTWAREThe microprocessor (module 2) includes the two PROM’s U3 and U5, which contain the software. Tolocate these PROM’s please see the photo of the microprocessor module given in section 4 in this manual.NOTE! If the software has to be changed, it is always necessary to change both PROM’s at a time.3.2 ALIGNMENT INSTRUCTIONSINTRODUCTIONThe measuring values indicated in chapter 5. CIRCUIT DESCRIPTION AND SCHEMATIC DIAGRAMSare typical values and as indicated it will be necessary to use instruments in absolute conformity with thelist given on the next page.9403PAGE 3-1