Motorola Vhf Manual
Have a look at the manual Motorola Vhf Manual online for free. It’s possible to download the document as PDF or print. UserManuals.tech offer 249 Motorola manuals and user’s guides for free. Share the user manual or guide on Facebook, Twitter or Google+.
Troubleshooting Flow Chart for VCO3-9 5.0 Troubleshooting Flow Chart for VCO Are Q3301 Base at 0.7V Collector at 4.5V Emitter at 110mV Are Q3304 Base at 2.4V Collector at 4.5V Emitter at 1.7VAre U3301 Pins 13 at 4.4V 15 at 1.1V 10 at 4.5V 16 at 1.9V Low or no RF Signal at TP3001 Visual check of board OK? 35mV DC at U3301 Pin 19 NO YES at base of Q3301 NO NO NO NONO YES YES YES YESYESLow or no RF Signal at input to PA5V DC at U3301 Pin 14&18 OK ? 4.8V DC at U3301 Pin 19 Is RF available at TP3401 YES YESYESYES YES NO NO NO NO NO Audio =180mVRMS at “-” side of D3362 2.5VDC at D3362 If C3362 and R3363 are OK, then replace D3362 Replace R3363 Replace R3364 NONO YES YES If R3402 and C3315 are OK, replace U3301 TX VCO RX VCO Correct ProblemVisual check of board OK? Make sure U3211 is working correctly and runner between U3211 Pin 1 and U3301 Pin 14 & 18 is OK Check runner between U3201 Pin 2 and U3301 Pin 19 Is RF available If all parts from U3301 Pin 8 to Base of Q3301 are OK, replace U3301 If all parts associated with the pins are OK, replace Q3301 Check parts between T3001 and Q3301 Power OK but no modulation If all parts from TP3401 of U3401 Pin 16 are OK, replace U3401 If all parts associated with the pins are OK, replace U3301 4.5V DC at U3301 Pin 3 OK? YES NO4.5V DC at U3301 Pin 3 OK? YES NO Make sure Synthesizer is working correctly and runner between U3201 Pin 28 and U4301 Pin 3 is OK 5V DC at U3301 Pin 14&18 OK ? OK? OK? If all parts associated with the pins are OK, replace Q3301
Chapter 4 VHF PCB/SCHEMATICS/PARTS LISTS 1.0 Allocation of Schematics and Circuit Boards 1.1 Controller Circuits The VHF circuits are contained on the printed circuit board (PCB) which also contains the Controller circuits. This Chapter shows the schematics for the VHF circuits only, refer to the Controller section for details of the related Controller circuits . The PCB component layouts and the Parts Lists in this Chapter show both the Controller and VHF circuit components. The VHF schematics and the related PCB and parts list are shown in the tables below. Table 4-1 VHF 1-25W Diagrams and Parts Lists PCB : 8486172B04 Main Board Top Side 8486172B04 Main Board Bottom SidePage 4-3 Page 4-4 SCHEMATICS Power Amplifier 1 - 25W FRACN Voltage Controlled Oscillator Receiver Front End IF Page 4-5 Page 4-6 Page 4-7 Page 4-8 Page 4-9 Parts List 8486172B04Page 4-10 Table 4-2 VHF 1-25W Diagrams and Parts Lists PCB : 8486172B06 Main Board Top Side 8486172B06 Main Board Bottom SidePage 4-13 Page 4-14 SCHEMATICS Power Amplifier 1 - 25W FRACN Voltage Controlled Oscillator Receiver Front End IF Page 4-15 Page 4-16 Page 4-17 Page 4-18 Page 4-19 Parts List 8486172B06Page 4-20
4-2VHF PCB/SCHEMATICS/PARTS LISTS Table 4-3 VHF 1-25W Diagrams and Parts Lists PCB : 8486172B07 Main Board Top Side 8486172B07 Main Board Bottom SidePage 4-23 Page 4-24 SCHEMATICS Power Amplifier 1 - 25W Voltage Controlled Oscillator Receiver Front End IF FRACN Page 4-15 Page 4-17 Page 4-18 Page 4-25 Page 4-26 Parts List 8486172B07Page 4-27 Table 4-4 VHF 25-45W Diagrams and Parts Lists PCB : 8486140B12 Main Board Top Side 8486140B12 Main Board Bottom SidePage 4-30 Page 4-31 SCHEMATICS Power Amplifier 25 - 45W FRACN Voltage Controlled Oscillator Receiver Front End IF Page 4-32 Page 4-26 Page 4-17 Page 4-18 Page 4-25 Parts List 8486140B12Page 4-33