LBI-38378D
REAR COVER ASSEMBLY
The Rear Cover Assembly houses the RF Board in the
The RF Board’s circuitry includes the transmitter, re- ceiver and the frequency synthesizer. This FM circuitry is under complete control of the microprocessor circuits. Con- trolling data sent to this assembly from the Control Board includes serial synthesizer data loading, transmitter/receiver enabling and a transmitter power level signal. The RF Board outputs the demodulated audio and a synthesizer lock status line to the Control Board. During transmitter operation, the RF power appears at the top antenna jack (or the UDC jack if the appropriate adapter plug is inserted). The Rear Cover Assembly maintenance manual contains a detailed circuit analysis, mechanical, outline and schematic diagrams for this assembly.
nal antenna can be mounted to the unit via the UDC. When an antenna is connected to the UDC, the antenna on the top of the radio is disabled.
BATTERY PACKS
The battery pack connects to the bottom of the unit and delivers a nominal 7.5 Volts dc to the radio. A recessed on/off switch for the radio is located on the battery pack. An internal fuse located in the radio’s Battery Plate protects the radio and battery from excessive current draw. The battery packs are available in several different capacities and sizes.
Radio contacts located on the top of the pack include switched power, ground, the speaker enabling contacts and a continuous power contact In addition, four contacts are lo- cated on the rear of the battery pack. These four contacts provide connections to the
FRONT COVER ASSEMBLY
The Front Cover Assembly houses all of the operating controls and the digital control circuitry for the radio. Board assemblies used in this assembly include the Control and LCD Boards and flex circuits include the Keypad, UDC and Speaker Flex circuits. The speaker, microphone and Battery Plate are also a part of this assembly. The complete assem- bly is housed in the
The Control Board located in the Front Cover Assembly is the largest and most complex board in the Front Cover Assembly. It contains all microcomputer and audio circuitry which controls the radio. See the maintenance manuals spe- cific to the Control Board or the Front Cover Assembly for service information on the related assembly.
ANTENNAS
Antennas are selected based on the operating frequency range of the radio. Table 1 lists the available antennas which mount in the antenna jack on the top of the radio. An exter-
The chargers utilize an internal thermistor in the battery pack to sense temperature and automatically control charge rate of the battery. This allows for a maximum charge rate without overheating the battery pack. All battery packs can be charged in less than 1 1/2 hours with the rapid type chargers. Nominal full charge time in a standard charger is 14 hours. The Service Section contains a detailed outline and schematic diagram of a typical battery pack. Further service information for the battery packs is also presented in the Service Section.
Chargers are available with nominal charge times of one hour (rapid) and fourteen hours (standard). Combinations include single (1) and multi (5 or 6) position, standard and rapid charge units. In addition, the vehicular chargers simul- taneously charge the battery while the radio is operating.
The battery packs should be fully charged in an appro- priate charger before they are placed into service. This ap- plies to new battery packs received from the factory and to battery packs that have been stored for long periods of time. A fully charged battery pack should have an
TABLE 1
USABLE FREQ. | OPTION |
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RANGE (MHz) | NUMBER | PART NUMBER | TYPE | BANDS |
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PANC1B | 19B234804P1 | Helical | Brown | |
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PANC1C | 19B234804P2 | Helical | Red | |
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157 - 174 | PANC1D | 19B234804P3 | Helical | Orange |
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