Galaxy DX 979 Service Manual
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Galaxy DX 979 Service Manual

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All manuals and user guides at all-guides.com
CB Radio
979
Model DX
Service Manual
Copyright Reserved

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Summary of Contents for Galaxy DX 979

  • Page 1 All manuals and user guides at all-guides.com CB Radio Model DX  Service Manual Copyright Reserved...

  • Page 2: Table Of Contents

    All manuals and user guides at all-guides.com TABLE OF DX 979 CONTENTS PAGE CHAPTER 1 SPECIFICATIONS General ..............

  • Page 3: Specifications

    All manuals and user guides at all-guides.com CHAPTER 1 DX 979 SPECIFICATIONS 1.0 GENERAL Model DX 979 Channels Frequency Range 26.965 – 27.405 MHz Emission Modes AM/USB/LSB Frequency Control Phase Lock Loop (PLL) synthesizer Frequency Tolerance 0.005 % Frequency Stability 0.001 %...

  • Page 4: Operation

    DX 979 Figure 2-1 Front Panel 2.0 INTRODUCTION This section explains the basic operating procedures for the DX 979 mobile CB radio. 2.1 CONTROLS AND CONNECTIONS 2.1.1 FRONT PANEL Refer to the above Figure 2-1 for the location of the following controls.
  • Page 5 All manuals and user guides at all-guides.com 5. MIC GAIN CONTROL: Adjusts the microphone gain in the transmit and PA modes. This controls the gain to the extent that full talk power is available several inches away from the microphone. In the Public Address (PA) mode, the control functions as the volume control. 6.
  • Page 6 4. EXT. SP: This jack accepts a 4 to 8 ohm, 5 watt external speaker. When the external speaker is connected to this jack, the built-in speaker will be disabled. 5. F.C.: This jack is used to connect the optional Galaxy FC347 six-digit frequency counter. All connections, including DC power, are provided to the FC347 through this jack.
  • Page 7 All manuals and user guides at all-guides.com 2.1.3 FREQUENCY CHART CHANNEL CHANNEL FREQUENCY CHANNEL CHANNEL FREQUENCY (MHz) (MHz) 26.965 27.215 26.975 27.225 26.985 27.255 27.005 27.235 27.015 27.245 27.025 27.265 27.035 27.275 27.055 27.285 27.065 27.295 27.075 27.305 27.085 27.315 27.105 27.325 27.115...

  • Page 8: Microphone

    All manuals and user guides at all-guides.com 2.2 MICROPHONE The receiver and transmitter are controlled by the push-to-talk switch on the microphone. Press the switch and the transmitter is activated, release the switch to receive. When transmitting, hold the microphone two inches from your mouth and speak clearly in a normal voice. The radio comes complete with a low impedance (500 ohm) dynamic microphone.

  • Page 9: Alternate Microphones And Installation

    All manuals and user guides at all-guides.com 2.4 ALTERNATE MICROPHONES AND INSTALLATION For best results, the user should select a low impedance dynamic type microphone or a transistorized microphone. Transistorized type microphones have a low output impedance characteristic. The microphones must be provided with a four-lead cable. The audio conductor and its shielded lead comprise two of the leads.

  • Page 10: Circuit Description

    DX 979 DESCRIPTION 3.0 INTRODUCTION This section explains the technical theory of operation for the DX 979 mobile CB radio. 3.1 PLL CIRCUIT The Phase Lock Loop (PLL) circuit is responsible for developing the receiver’s first local oscillator signal and the transmitter’s exciter signal. The PLL circuit consists primarily of IC2, IC3, Q25, Q29 and Q28.
  • Page 11 All manuals and user guides at all-guides.com - 10 -...

  • Page 12: Alignment

    All manuals and user guides at all-guides.com CHAPTER 4 DX 979 ALIGNMENT 4.0 REQUIRED TEST EQUIPMENT DC Power Supply (13.8VDC, 10A) Frequency Counter (100 MHz) RF Wattmeter (10W) RF Signal Generator (100 MHz) Multi-meter Automatic Distortion Meter Automatic Modulation Meter...
  • Page 13 All manuals and user guides at all-guides.com 4.1.2 TRANSMITTER ALIGNMENT ADJUST ITEM U.U.T. SETTING MEASUREMENT POINT BIAS Current Set radio to CH 19 USB TX mode. Modulation Off. Remove “short PCB” from TP7, TP8, TP9. Connect current meter to TP7(+) and TP9 (-) VR12 50 mA Connect current meter to TP7(+) and TP8 (-)
  • Page 14 All manuals and user guides at all-guides.com 4.1.3 RECEIVER ALIGNMENT ADJUST ITEM U.U.T. SETTING MEASUREMENT POINT AM Sensitivity Set radio to CH 19 AM RX mode. Set RF GAIN Fully Clockwise. L2,L3,L5,L6, Audio Output > 2V Set SQ Fully Counter Clockwise. L7,L8,L9,L10 S/N >...
  • Page 15 All manuals and user guides at all-guides.com Figure 4-1 Transmitter test setup Figure 4-2 Receiver test setup - 14 -...
  • Page 16 All manuals and user guides at all-guides.com DX 979 MAIN PCB ADJUSTMENT LOCATION DRIVER BIAS FINAL BIAS RF METER AM LOW POWER AM HI POWER AM LOW POWER AM MOD METER SSB S-METER AM S-METER 10.240 MHz ADJUST CARRIER BALANCE...

  • Page 17: Maintenance

    All manuals and user guides at all-guides.com CHAPTER 5 DX 979 MAINTENANCE 5.0 PRECAUTIONS The inherent quality of the solid-state components used in this transceiver will provide many years of continuous use. Taking the following precautions will prevent damage to the transceiver.
  • Page 18 All manuals and user guides at all-guides.com CHAPTER 6 DIAGRAMS & DX 979 PARTS LIST 6.0 GENERAL Information on most electrical and mechanical parts is included in the parts list. The reference designators are in alphanumeric order. - 17 -...
  • Page 19 All manuals and user guides at all-guides.com DX 979 ROTARY SWITCH PCB (EPT092920Z) (SMD-COPPER SIDE) ( COMPONENT SIDE ) - 18 -...
  • Page 20 All manuals and user guides at all-guides.com PART LIST: DX 979 ROTARY SW. P.C.B REFERENCE RANGER PART ITEM DESCRIPTION NUMBER NUMBER EPT092920Z ROTARY SW PCB CHIP/F/R 0.0 Ω 0.1W RCY010004Z R207,R210,R218 CHIP/F/R 330 Ω 0.1W RCY013314Z R201 CHIP/F/R 680 Ω 0.1W...
  • Page 21 All manuals and user guides at all-guides.com DX 979 DISPLAY PCB (EPT092930Z) ( COMPONENT SIDE ) ( COMPONENT SIDE ) ( COPPER SIDE ) - 20 -...
  • Page 22 All manuals and user guides at all-guides.com PART LIST: DX 979 DISPLAY P.C.B REFERENCE RANGER PART ITEM DESCRIPTION NUMBER NUMBER EPT092930Z DISPLAY PCB CHIP/F/R 680 Ω 0.1W R301,R302,R303,R304, RCY016814Z R305,R306,R307 CHIP/F/R 1K Ω 0.1W R308 RCY011024Z D301,D302 EDSS00355Y DIODE 1SS355...
  • Page 23 All manuals and user guides at all-guides.com DX 979 (DIM-PWR/MIC-RF/VOL-SQ CONTROL) VR PCB (EPT092940Z) ( COMPONENT SIDE ) ( COPPER SIDE ) - 22 -...
  • Page 24 All manuals and user guides at all-guides.com PART LIST: DX 979 DIM-PWR/MIC-RF/VOL-SQ CONTROL, VR P.C.B REFERENCE RANGER PART ITEM DESCRIPTION NUMBER NUMBER EPT092940Z VR PCB CHIP/F/R 6.8K Ω 0.1W R402 RCY016824Z CHIP/F/R 10K Ω 0.1W R401 RCY011034Z C401,C402 CK1102AB5X CHIP/C .001uF 50VW...
  • Page 25 All manuals and user guides at all-guides.com DX 979 (TALKBACK/CLARIFIER CONTROL) VR PCB (EPT092950Z) ( COMPONENT SIDE ) ( COPPER SIDE ) PART LIST: DX 979 TALKBACK/CLARIFIER CONTROL, VR P.C.B REFERENCE RANGER PART ITEM DESCRIPTION NUMBER NUMBER EPT092950Z TB PCB...
  • Page 26 All manuals and user guides at all-guides.com DX 979 METER PCB (EPT092961Z) ( COMPONENT SIDE ) ( COPPER SIDE ) ( COPPER SIDE-SMD ) - 25 -...
  • Page 27 All manuals and user guides at all-guides.com PART LIST: DX 979 METER PCB (Dimmer Circuit) REFERENCE RANGER PART ITEM DESCRIPTION NUMBER NUMBER EPT092961Z METER PCB CHIP/F/R 15 Ω 0.1W R603 RCY011504Z CHIP/F/R 47 Ω 1/4W R606,R607 RCY144704Z R610 RCY011024Z CHIP/F/R 1KΩ 0.1W...
  • Page 28 All manuals and user guides at all-guides.com DX 979 ANTENNA PCB (EPT360042Z) (COPPER SIDE-SMD ) ( COPPER SIDE ) ( COMPONENT SIDE ) PART LIST: DX 979 ANT P.C.B REFERENCE RANGER PART ITEM DESCRIPTION NUMBER NUMBER EPT360042Z ANT P.C.B RCY010004Z 0 OHM 0.1W...
  • Page 29 All manuals and user guides at all-guides.com DX 979 MAIN PCB (EPT092913Z) ( COMPONENTS SIDE ) - 28 -...
  • Page 30 All manuals and user guides at all-guides.com DX 979 MAIN PCB (EPT092913Z) ( COPPER SIDE ) - 29 -...
  • Page 31 All manuals and user guides at all-guides.com PART LIST DX 979 MAIN PCB REFERENCE RANGER DESCRIPTION C137 CC0501515L 150PF 50WV NUMBER PART NO. C31,136 CC0502715L 270PF 50WV C11,14 CC0503315L 330PF 50WV EPT092913Z MAIN PCB CC0505615L 560PF 50WV EPT120060A DCB+ PCB...
  • Page 32 All manuals and user guides at all-guides.com 276,132,239 ECCHK16096 470UH CV038200AZ TRIMMER/C L503 ECCHK16000 0.47UH L26,27,46 ECCHK16003 470UH (CV38D2001) ECCHK16004 1.1MH EI-19 C80,181 CE0252267Z 22UF 25WV L33,37 ECCHK16070 22UH C37,175,33,144,38 CE0254767Z 47UF 25WV ECCHK16176 4.7UH C156,238,293,107 CE0161077Z 100UF 16WV ECCHK16246 22UH C252 CE0162277Z...
  • Page 33 All manuals and user guides at all-guides.com DX 979 SCHEMATIC DIAGRAM (CONTROL PCB)
  • Page 34 All manuals and user guides at all-guides.com DX 979 SCHEMATIC DIAGRAM (MAIN PCB)
  • Page 35 All manuals and user guides at all-guides.com DX 979 EXPLODE DRAWING DX 979 MECHANICAL PART...
  • Page 36 All manuals and user guides at all-guides.com UPDATES & CORRECTIONS Any updates or corrections to this Service Manual will be included in the Tech Support section of our website at www.GalaxyRadios.com.
  • Page 37 All manuals and user guides at all-guides.com Two Year Warranty This new Galaxy radio is covered by a two year limited warranty. Here are the details. • All of our Galaxy radio model numbers begin with the letters “DX” and are covered by our Limited Two Year Parts and Labor Warranty.
  • Page 38 All manuals and user guides at all-guides.com ATS979010A July, 2003...

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