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Galaxy DX 979 Service Manual

Other manuals for DX 979: Owner's manual

Summary of DX 979

  • Page 1

    Cb radio model dx 979 service manual copyright reserved.

  • Page 2: Dx 979

    - 1 - dx 979 table of contents page chapter 1 specifications 1.0 general . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1 transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....

  • Page 3: Dx 979

    - 2 - 1.0 general model dx 979 channels 40 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 % operating temperature range -30 ° c to +50 ° c microphone dynamic ptt, 500 Ω input volt...

  • Page 4: Dx 979

    - 3 - 20 mod s 3 1 swr pwr 0 dx 979 +20 12 80 db +40 100% +60 3 6 7 5 40 9 60 2 1 1.5 3 1 18 ma x off talkback dim pwr mic rf off vol sq usb am lsb clarifier nb/anl pa cb mod swr pwr rx/tx swr 8 12 9 10 11 14 13 18 15 1 2 3 5 4 7 6 16 17 dx 979 chapter 2 operation figure 2-1 front panel 2.0 introduc...

  • Page 5

    - 4 - 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. Rf power control: this...

  • Page 6

    - 5 - rear panel figure 2-2 represents the location of the following connections: figure 2-2 rear panel 1. Antenna: this jack accepts a 50 ohm coaxial cable with a pl-259 type plug. 2. Dc power: this jack accepts the 13.8v dc power cable with built-in fuse. The power cord provided with the radio has...

  • Page 7

    - 6 - 2.1.3 frequency chart channel channel frequency (mhz) channel channel frequency (mhz) 1 26.965 21 27.215 2 26.975 22 27.225 3 26.985 23 27.255 4 27.005 24 27.235 5 27.015 25 27.245 6 27.025 26 27.265 7 27.035 27 27.275 8 27.055 28 27.285 9 27.065 29 27.295 10 27.075 30 27.305 11 27.085 31 27.3...

  • Page 8

    - 7 - 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 ...

  • Page 9

    - 8 - 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 a...

  • Page 10: Dx 979

    - 9 - dx 979 chapter 3 circuit 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 excit...

  • Page 11

    - 10 -.

  • Page 12: Dx 979

    - 11 - dx 979 chapter 4 alignment 4.0 required test equipment c dc power supply (13.8vdc, 10a) d rf wattmeter (10w) e multi-meter f automatic modulation meter g audio signal generator h frequency counter (100 mhz) i rf signal generator (100 mhz) j automatic distortion meter k oscilloscope (50 mhz) l...

  • Page 13

    - 12 - 4.1.2 transmitter alignment item u.U.T. Setting adjust point measurement 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 (-) connect current meter to tp7(+) and tp8 (-) vr12 vr10 50 ma 100 ma ssb apc s...

  • Page 14

    - 13 - 4.1.3 receiver alignment item u.U.T. Setting adjust point measurement am sensitivity set radio to ch 19 am rx mode. Set rf gain fully clockwise. Set sq fully counter clockwise. Set vol control at 2 o’clock. Set nb/anl switch to off position. Set clarifier control to 12 o’clock. Connect rf sg ...

  • Page 15

    - 14 - figure 4-1 transmitter test setup figure 4-2 receiver test setup.

  • Page 16

    - 15 - dx 979 main pcb adjustment location driver bias final bias rf meter alc am mod am low power apc am hi power am mod meter ssb s-meter am s-meter ssb squelch am squelch tx offset carrier balance 10.240 mhz adjust am low power am mod am ssb.

  • Page 17: Dx 979

    - 16 - dx 979 chapter 5 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. (i) never key the transmitter unless an antenna or suita...

  • Page 18: Dx 979

    - 17 - dx 979 chapter 6 diagrams & 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..

  • Page 19: Dx 979

    - 18 - dx 979 rotary switch pcb (ept092920z) (smd-copper side) ( component side ).

  • Page 20

    - 19 - part list: dx 979 rotary sw. P.C.B item reference number ranger part number description 1 ept092920z rotary sw pcb 2 r207,r210,r218 rcy010004z chip/f/r 0.0 Ω 0.1w 3 r201 rcy013314z chip/f/r 330 Ω 0.1w 4 r202,r203,r204,r205, r206 rcy016814z chip/f/r 680 Ω 0.1w 5 r215 rcy014724z chip/f/r 4.7k Ω...

  • Page 21

    - 20 - dx 979 display pcb (ept092930z) ( component side ) ( component side ) ( copper side ).

  • Page 22

    - 21 - part list: dx 979 display p.C.B item reference number ranger part number description 1 ept092930z display pcb 2 r301,r302,r303,r304, r305,r306,r307 rcy016814z chip/f/r 680 Ω 0.1w 3 r308 rcy011024z chip/f/r 1k Ω 0.1w 4 d301,d302 edss00355y diode 1ss355 5 led201,led202 ex01y40114 led lamps km-2...

  • Page 23: (Ept092940Z)

    - 22 - dx 979 (dim-pwr/mic-rf/vol-sq control) vr pcb (ept092940z) ( component side ) ( copper side ).

  • Page 24

    - 23 - part list: dx 979 dim-pwr/mic-rf/vol-sq control, vr p.C.B item reference number ranger part number description 1 ept092940z vr pcb 2 r402 rcy016824z chip/f/r 6.8k Ω 0.1w 3 r401 rcy011034z chip/f/r 10k Ω 0.1w 4 c401,c402 ck1102ab5x chip/c .001uf 50vw 5 c403,c404 ck1103ab5x chip/c .01uf 50vw 6 ...

  • Page 25: (Ept092950Z)

    - 24 - dx 979 (talkback/clarifier control) vr pcb (ept092950z) ( component side ) ( copper side ) part list: dx 979 talkback/clarifier control, vr p.C.B item reference number ranger part number description 1 ept092950z tb pcb 2 vr501 (clarifier) rv10203528 vr 1kb 3 vr502 (talkback) rv20203558 vr 20k...

  • Page 26

    - 25 - dx 979 meter pcb (ept092961z) ( component side ) ( copper side ) ( copper side-smd ).

  • Page 27

    - 26 - part list: dx 979 meter pcb (dimmer circuit) item reference number ranger part number description 1 ept092961z meter pcb 2 r603 rcy011504z chip/f/r 15 Ω 0.1w 3 r606,r607 rcy144704z chip/f/r 47 Ω 1/4w 4 r610 rcy011024z chip/f/r 1k Ω 0.1w 5 r605 rcy013324z chip/f/r 3.3k Ω 0.1w 6 r604,r611 rcy01...

  • Page 28

    - 27 - dx 979 antenna pcb (ept360042z) (copper side-smd ) ( copper side ) ( component side ) part list: dx 979 ant p.C.B item reference number ranger part number description 1 ept360042z ant p.C.B 2 r9 rcy010004z 0 ohm 0.1w 3 r1 rcy014714z 470 ohm 0.1w 4 r3,r4 rcy011014z 100 ohm 0.1w 5 r2 rcy013314z...

  • Page 29: Dx 979 Main Pcb (Ept092913Z)

    - 28 - dx 979 main pcb (ept092913z) ( components side ).

  • Page 30: Dx 979 Main Pcb (Ept092913Z)

    - 29 - dx 979 main pcb (ept092913z) ( copper side ).

  • Page 31

    - 30 - part list dx 979 main pcb reference number ranger part no. Description ept092913z main pcb ept120060a dcb+ pcb r19,305,258(b239) rcp160004z 0 Ω 1/16w r246 rcp161004z 10 Ω 1/16w r267 rcp161504z 150 Ω 1/16w 241 rcp162204z 220 Ω 1/16w r133,213,253,282,113 rcp164704z 47 Ω 1/16w r130,215,220,249 r...

  • Page 32

    - 1 - - 31- 276,132,239 vc1 cv038200az trimmer/c 20p (cv38d2001) c80,181 ce0252267z 22uf 25wv c37,175,33,144,38 ce0254767z 47uf 25wv c156,238,293,107 ce0161077z 100uf 16wv c252 ce0162277z 220uf 16wv c152,179 ce0163377z 330uf 16wv c91 ce0104777z 470uf 10wv c243,248 ce0251087z 1000uf 25wv c35 cem25476...

  • Page 33

    Dx 979 schematic diagram (control pcb).

  • Page 34

    Dx 979 schematic diagram (main pcb).

  • Page 35

    Dx 979 mechanical part dx 979 explode drawing.

  • Page 36: Www.Galaxyradios.Com.

    Any updates or corrections to this service manual will be included in the tech support section of our website at www.Galaxyradios.Com. Updates & corrections.

  • Page 37: Two Year Warranty

    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. • “limited” means that we will repair problems caused by fact...

  • Page 38

    Ats979010a july, 2003.