Motorola GM160 Service Information
Gm series professional radio uhf (403-470mhz)
Hide thumbs
Also See for GM160:
- User manual (44 pages) ,
- Basic service manual (46 pages) ,
- Service information (34 pages)
Related Manuals for Motorola GM160
Summary of Contents for Motorola GM160
- Page 1 Professional Radio GM Series UHF (403-470MHz) Service Information Issue: August 2002...
-
Page 2: Computer Software Copyrights
Accordingly, any copyrighted Motorola computer programs contained in the Motorola products described in this manual may not be copied or reproduced in any manner without the express written permission of Motorola. Furthermore, the purchase of Motorola... -
Page 3: Table Of Contents
Table of Contents Chapter 1 MODEL CHART AND TECHNICAL SPECIFICATIONS 1.0 GM140/GM160 Model Chart................1-1 2.0 GM340/GM360/GM380 Model Chart ..............1-1 3.0 GM640/GM660/GM1280 Model Chart ..............1-2 4.0 Technical Specifications ..................1-3 Chapter 2 THEORY OF OPERATION 1.0 Introduction ......................2-1 2.0 UHF (403-470MHz) Receiver ................2-1 2.1 Receiver Front-End ..................2-1... - Page 4 Chapter 3 TROUBLESHOOTING CHARTS 1.0 Troubleshooting Flow Chart for Receiver (Sheet 1 of 2) ........3-1 1.1 Troubleshooting Flow Chart for Receiver (Sheet 2 of 2) ........3-2 2.0 Troubleshooting Flow Chart for 25W Transmitter (Sheet 1 of 3) ......3-3 2.1 Troubleshooting Flow Chart for 25W Transmitter (Sheet 2 of 3) ......
-
Page 5: Model Chart And Technical Specifications
GM140/GM160 Model Chart GM Series UHF 403-470 MHz Model Description MDM25RKC9AN1_E GM140, 403-470 MHz, 25-40W, 4 Ch MDM25RKF9AN5_E GM160, 403-470 MHz, 25-40W, 128 Ch MDM25RHC9AA1_E GM140, 403-470 MHz, 1-25W, 4 Ch MDM25RHF9AA5_E GM160, 403-470 MHz, 1-25W, 128 Ch Item Description... -
Page 6: Gm340/Gm360/Gm380 Model Chart
MODEL CHART AND TECHNICAL SPECIFICATIONS GM340/GM360/GM380 Model Chart GM Series UHF 403-470 MHz Model Description MDM25RHC9AN1_E GM340, 403-470 MHz, 1-25W, 6 Ch MDM25RHF9AN5_E GM360, 403-470 MHz, 1-25W, 255 Ch MDM25RHC9AN8_E GM380, 403-470 MHz, 1-25W, 255 Ch Databox, 403-470 MHz, 1-25W, 16 Ch MDM25RHA9AN0_E Item Description... -
Page 7: Gm640/Gm660/Gm1280 Model Chart
GM640/GM660/GM1280 Model Chart GM640/GM660/GM1280 Model Chart GM Series UHF 403-470 MHz Model Description MDM25RHC9CK1_E GM640, 403-470 MHz, 1-25W, 6 Ch MDM25RHF9CK5_E GM660, 403-470 MHz, 1-25W, 255 Ch MDM25RHN9CK8_E GM1280, 403-470 MHz, 1-25W, 255 Ch Databox, 403-470 MHz, 1-25W, 16 Ch MDM25RHA9CK7_E Item Description... -
Page 8: Technical Specifications
72mm x 185mm x 188mm (add 8mm for Volume Knob) Dimensions: H x W x D (mm) Depth excluding knobs Databox 44mm x 168mm x 161mm Weight GM140/340/640 1400gr Weight GM160/360/660 1400gr Weight GM380/1280 1500gr Weight Databox 1220gr Sealing: Withstands rain testing per... - Page 9 Technical Specifications Transmitter 403-470 *Frequencies - Full Bandsplit Channel Spacing 12.5/20/25 kHz Frequency Stability ±2.0 ppm (-30°C to +60°C, +25° Ref.) Power 1-25W/25-40W ±2.5 @ 12.5 kHz Modulation Limiting ±4.0 @ 20 kHz ±5.0 @ 25 kHz -40 dB @ 12.5kHz FM Hum &...
- Page 10 MODEL CHART AND TECHNICAL SPECIFICATIONS...
-
Page 11: Theory Of Operation
Chapter 2 THEORY OF OPERATION Introduction This Chapter provides a detailed theory of operation for the UHF circuits in the radio. For details of the theory of operation and trouble shooting for the the associated Controller circuits refer to the Controller Section of this manual. -
Page 12: Front-End Band-Pass Filters & Pre-Amplifier
THEORY OF OPERATION There are two 2-pole 44.85 MHz crystal filters in the high-IF section and 2 pairs of 455 kHz ceramic filters in the low-IF section to provide the required adjacent channel selectivity .The correct pair of ceramic filters for 12.5 or 25KHz channel spacing is selected via control line BWSELECT. The second IF at 455 kHz is mixed, amplified and demodulated in the IF IC. -
Page 13: Uhf (403-470Mhz) Transmitter Power Amplifier (Pa) 25 W
UHF (403-470MHz) Transmitter Power Amplifier (PA) 25 W produce the low IF signal at 455 kHz. The 2nd LO frequency is determined by crystal Y3101. The low IF signal is amplified and filtered by an external pair of 455 kHz ceramic filters FL3112, FL3114 for 20/25 kHz channel spacing or FL3111,FL3113/F3115 for 12.5 kHz channel spacing. -
Page 14: Power Controlled Driver Stage
THEORY OF OPERATION controlled by a DC voltage applied to pin 1 from the op-amp U4402-1, pin 1. The control voltage simultaneously varies the bias of two FET stages within U4401. This biasing point determines the overall gain of U4401 and therefore its output drive level to Q4421, which in turn controls the output power of the PA. -
Page 15: Antenna Switch
UHF (403-470MHz) Transmitter Power Amplifier (PA) 25 W Antenna Switch The antenna switch consists of two PIN diodes, D4471 and D4472. In the receive mode, both diodes are off. Signals applied at the antenna jack J4401 are routed, via the harmonic filter, through network L4472, C4474 and C4475, to the receiver input. -
Page 16: Uhf (403-470Mhz) Frequency Synthesis
THEORY OF OPERATION UHF (403-470MHz) Frequency Synthesis The synthesizer subsystem consists of the reference oscillator (Y4261 or Y4262), the Low Voltage Fractional-N synthesizer (LVFRAC-N, U4201), and the Voltage Controlled Oscillator VCO. Reference Oscillator The reference oscillator (Y4262) contains a temperature compensated crystal oscillator with a frequency of 16.8 MHz. -
Page 17: Voltage Controlled Oscillator (Vco)
UHF (403-470MHz) Frequency Synthesis A voltage of 5V applied to the super filter input (U4201 pin 30) supplies an output voltage of 4.5 VDC(VSF) at pin 28. It supplies the VCO, VCO modulation bias circuit (via R4322) and the synthesizer charge pump resistor network (R4251, R4252). The synthesizer supply voltage is provided by the 5V regulator U4211. -
Page 18: Synthesizer Operation
THEORY OF OPERATION The VCOBIC together with Fractional-N synthesizer (U4201) generates the required frequencies in both transmit and receive modes. The TRB line (U4301 pin 19) determines which tank circuits and internal buffers are to be enabled. A high level on TRB enables TX tank and TX output (pin 10), and a low enables RX tank and RX output (pin 8). -
Page 19: Power Controlled Stage
UHF (403-470MHz) Transmitter Power Amplifier (PA) 40W UHF (403-470MHz) Transmitter Power Amplifier (PA) 40W The radio’s 40 W PA is a four stage amplifier used to amplify the output from the VCOBIC to the radio transmit level. It consists of the following four stages in the line-up. The first stage is a LDMOS predriver (U4401) that is controlled by pin 4 of PCIC (U4501) via Q4473 (CNTLVLTG). -
Page 20: Driver Stage
2-10 THEORY OF OPERATION Driver Stage The following stage is an enhancement-mode N-Channel MOSFET device (Q4431) providing a gain of 10dB. This device also requires a positive gate bias and a quiescent current flow for proper operation. The voltage of the line Bias_2_UHF_PA_1 is set in transmit mode by the ASFIC and fed to the gate of Q4431 via the resistive network R4632, R4631, R4485 and R4486. -
Page 21: Power Control
UHF (403-470MHz) Transmitter Power Amplifier (PA) 40W 2-11 Power Control The transmitter uses the Power Control IC (PCIC, U4501) to control the power output of the radio. A portion of the forward RF power from the transmitter is sampled by the bi-directional coupler and rectified, to provide a DC voltage to the RFIN port of the PCIC (pin 1) which is proportional to the sampled RF power. - Page 22 2-12 THEORY OF OPERATION...
-
Page 23: Troubleshooting Flow Chart For Receiver (Sheet 1 Of 2)
Chapter 3 TROUBLESHOOTING CHARTS Troubleshooting Flow Chart for Receiver (Sheet 1 of 2) START Bad SINAD Bad 20dB Quieting No Recovered Audio Check Controller Audio at (in the case of no audio) pin 8 of OR ELSE go to “B” U3101 ? Spray or inject 44.85MHz into XTAL Filter FL3101... -
Page 24: Troubleshooting Flow Chart For Receiver (Sheet 2 Of 2)
TROUBLESHOOTING CHARTS Troubleshooting Flow Chart for Receiver (Sheet 2 of 2) Inject RF into J4401 Trace IF signal from C3101 to IF Signal at signal at Q3102 Q3101. Check for C3101? collector? bad XTAL filter. Before replacing U3101, check U3101 voltages. 1st LO level Signal at Check FGU... -
Page 25: Troubleshooting Flow Chart For 25W Transmitter (Sheet 1 Of 3)
Troubleshooting Flow Chart for 25W Transmitter (Sheet 1 of 3) Troubleshooting Flow Chart for 25W Transmitter (Sheet 1 of 3) START No or too low Power when keyed Check if Pressure Pad closes S5440 Check Components between Current Q4441 and RF Output, >500mA &... -
Page 26: Troubleshooting Flow Chart For 25W Transmitter (Sheet 2 Of 3)
TROUBLESHOOTING CHARTS Troubleshooting Flow Chart for 25W Transmitter (Sheet 2 of 3) Check PA Stages No or too low Power when keyed DC Voltage If U4201 Pin 2 is high, at U4501 replace PCIC Pin 23 =0? Check Resistive Net- >6 <2V Voltage at... -
Page 27: Troubleshooting Flow Chart For 25W Transmitter (Sheet 3 Of 3)
Troubleshooting Flow Chart for 25W Transmitter (Sheet 1 of 3) Troubleshooting Flow Chart for 25W Transmitter (Sheet 3 of 3 Check Final PA Stage Supply Voltage Bias 2 DC Voltage at Replace Q4441 TP4406? 1-4V Check Components ASFIC RF Voltage between ASFIC and U0221 Pin 6 Check FGU (U4301) -
Page 28: Troubleshooting Flow Chart For 40W Transmitter
TROUBLESHOOTING CHARTS Troubleshooting Flow Chart for UHF 40W Transmitter START No power Is Vctrl Check Is Q4473 Check there? MOSBIAS_2 ASFIC Change Q4473 Check voltage Check on Pin 4 U4501 Check PCIC_MOSBIAS_1 PCIC Check R4422-5 and go back to top Check voltage on Pin 5 U4501 Are D4471 &... -
Page 29: Troubleshooting Flow Chart For Synthesizer
Troubleshooting Flow Chart for Synthesizer Troubleshooting Flow Chart for Synthesizer Start Check 5V at U4201 Regulator pins 5, 20, 34 U4211 & 36 Visual Correct check of the Problem Board Check D4201, C4202, C4203, & C4206 16.8MHz 16.8MHz Replace U4201 Pin 47 signal at Signal at U4201 at pin 6 of... -
Page 30: Troubleshooting Flow Chart For Vco
TROUBLESHOOTING CHARTS Troubleshooting Flow Chart for VCO Low or no RF Signal Low or no RF Signal TX VCO RX VCO at input to PA at TP4003 Visual check Visual check Correct of board of board Problem Make sure Synthesizer is 4.5V DC 4.5V DC working correctly and runner... -
Page 31: Allocation Of Schematics And Circuit Boards
Chapter 4 UHF PCB/SCHEMATICS/PARTS LISTS Allocation of Schematics and Circuit Boards Controller Circuits The UHF circuits are contained on the printed circuit board (PCB) which also contains the Controller circuits. This Chapter shows the schematics for the UHF circuits only, refer to the Controller section for details of the related Controller circuits . - Page 32 UHF PCB/Schematics/parts lists Table 4-3 UHF 1-25W Diagrams and Parts Lists PCB : 8485670z03 Main Board Top Side Page 4-23 8485670z03 Main Board Bottom Side Page 4-24 SCHEMATICS Power Amplifier 1 - 25W Page 4-25 FRACN Page 4-26 Voltage Controlled Oscillator Page 4-27 Receiver Front End Page 4-28...