Motorola Mtx Series Detailed Rev 6881088c46 E Manual
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FMR-2045A-2December 26, 2003 UHF Band 2 Theory of Operation: Synthesizer 41 The Frequency Generation Circuitry is composed of two main ICs: Fractional-N synthesizer (U201) VCO/Buffer IC (U241) Designed in conjunction to maximize compatibility, the two ICs provide many of the functions that normally would require additional circuitry. The synthesizer block diagram illustrates the interconnect and support circuitry used in the region. Refer to the relevant schematics for the reference designators....
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December 26, 2003FMR-2045A-2 42UHF Band 2 Theory of Operation: Voltage-Controlled Oscillator (VCO) The loop filter, which consists of C231, C232, C233, R231, R232, and R233, provides the necessary DC steering voltage for the VCO and determines the amount of noise and spur passing through. In achieving fast locking for the synthesizer, an internal adapt charge pump provides higher current at pin 45 of U201 to put the synthesizer within the lock range. The required frequency is then locked by normal...
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FMR-2045A-2December 26, 2003 UHF Band 2 Theory of Operation: Voltage-Controlled Oscillator (VCO) 43 The VCOBIC (U241), in conjunction with the Fractional-N synthesizer (U201), generates RF in both the receive and the transmit modes of operation. The TRB line (U241 pin 19) determines which oscillator and buffer will be enabled. A sample of the RF signal from the enabled oscillator is routed from U241 pin 12, through a low pass filter, to the prescaler input (U201 pin 32). After frequency comparison in...
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December 26, 2003FMR-2045A-2 This page intentionally left blank. 44UHF Band 2 Theory of Operation: Voltage-Controlled Oscillator (VCO)
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Chapter 5 UHF Band 2 CB Layouts, Schematic Diagrams, and Parts List 5.1 Notes For All Schematics and Circuit Boards * Component is frequency sensitive. Refer to the Electrical Parts List for value and usage. 1.Unless otherwise stated, resistances are in Ohms (k = 1000), and capacitances are in picofarads (pF) or microfarads (µF). 2.DC voltages are measured from point indicated to chassis ground using a Motorola DC multimeter or equivalent. Transmitter measurements should be made with a 1.2 µH choke in...
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December 26, 2003FMR-2045A-2 This page intentionally left blank. 46UHF Band 2 CB Layouts, Schematic Diagrams, and Parts List: Notes For All Schematics and Circuit Boards
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Circuit Board/Schematic Diagrams and Parts List 47 FMR-2045A-2 December 26, 2003 5.2 Circuit Board/Schematic Diagrams and Parts List Figure 5-1. UHF Band 2 (450-527 MHz) Main Board Top Side PCB No. 8486686Z01 C425 C426 C432 1 J400 22 21 8 71 U40532 17 16 1 U406 1 4 5 8 U407C423 E407E408 E409R410 R418 R437 C404C427 C428 C443C444 C471 C472 C473 40 1 21 L401R435 RT400 TP401 TP402 TP410 VR447 VR449 CR413 2220J403 L400 4 3 Q417 R421TP405TP406 TP415 VR434 VR450C441 C490 C491 C492 C493 C494 C495 C496C497 R450...
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48Circuit Board/Schematic Diagrams and Parts ListDecember 26, 2003FMR-2045A-2 Figure 5-2. UHF Band 2 (450-527 MHz) Main Board Bottom Side PCB No. 8486686Z01 4 5 32 S502 2C8C 4 S501 2 3 4 1 J101 J102 C108 CR103 CR160 P1004 3 Q111R101R170 C132 C172 C173 CR105 H101 R133 R172 C105 C123 C126 C128 C130 C133 C134 C135 C138C150 C151C152 C170 C174 E101 L112 R102R109 R130 R131R132 R136 117 9 25 U102 C318CR306 CR501 F501 R329 SH304 VR439 C306 C307 C309C310 C311 C312 C313 C314 C315 C316 C317C321 C380 CR303 CR304...
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Circuit Board/Schematic Diagrams and Parts List49FMR-2045A-2December 26, 2003 Figure 5-3. UHF Band 2 Controls and Switches Schematic Diagram 390nHL505 RADIO_CODE BATTERY_CONTACT BATT- BATT+ B501 CONN_J DATA 2 NEG 1 POS 3 1 2CR501VR439 10V 6.8VVR506 C503 100pF 124V F501 2 BATT_CODE UNSWB+ R507 0 0.47uFC502 C505TAB2 7 2 100pFS502 SWITCH 4 1 LOW5 3 HIGH TAB1 6 VR5016.8V MECH_SWB+ Vdda B503 if B504 LI_ION VOL P100 SB1 SB3 SB2 .01uF C521 C523 .01uF .01uF C522PTT VR442 6.8V VR444 6.8V 6.8V VR441VR440 6.8V...
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50Circuit Board/Schematic Diagrams and Parts ListDecember 26, 2003FMR-2045A-2 Figure 5-4. UHF Band 2 Receiver Front End Schematic Diagram RXFE Top Shield1 SHIELDSH301 RXFE Bottom Shield RX Mixer Diod Shield1 SHIELDSH302 SH304 SHIELD 1Mixer ShieldSH303 SHIELD 1 4.3pFC303 CR301 12pF C302 L301 11.03nHR301 100K C301 8.2pF RX_IN100K R302 C304 11pF100pF C305 11.03nH L302CR3023 1 CR303 2 C308 100pF 100pFC307C310 100pF C309 100pF 2.7 R328 1.5K R303 Q301 13 20.1uF C314 R304 12KR305 470 L304 180nHC321 100pFC315...