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DJ-175
Service Manual
29 pgs696.02 Kb0
User Manual
60 pgs1.57 Mb0

Alinco DJ-175 Service Manual

Service Manual
DJ-175
Specifications Circuit Description
Parts List
Exploded View PC Board View
Adjustment
ALINCO, INC
SPECIFICATIONS DJ-175
<GRNERAL>
Frequency range:
T: TX 144 ~ 147.995MHz *144 ~ 147.995MHz
RX 136 ~ 173.995MHz *144 ~ 147.995MHz
E: TX 144 ~ 145.995MHz *144 ~ 145.995MHz
RX 144 ~ 145.995MHz *144 ~ 145.995MHz
TFH: TX 136 ~ 173.995MHz *150 ~ 173.995MHz
RX 136 ~ 173.995MHz *150 ~ 173.995MHz
* Guaranteed range per specifications
Modulation: Channel steps: Memory channels:
Antenna impedance:
Frequency stability: Microphone impedance: Power supply:
Current drain (Approx.):
Temperature range: Ground:
Dimension:
Weight:
DTMF:
Subaudible Tone (CTCSS):
Digital Code SQ. (DCS):
F3E (FM), F2D* *T/E models only 5, 10, 12.5, 20, 25 & 30KHz 200 channels + 1 CALL channel + 1 Repeater-Access function memory 50 Q unbalanced +/- 2.5ppm 2k ohm nominal
7.2V/ 7.4V (Battery only)
1.5A Transmit high at 5W 250mA Receive at 500mW 70mA Stand-by 30mA Battery save on
-10 ~ +45°C (+14 ~ 113°F) Negative ground
58(W) x 107.5(H) x 36.3(D) mm
2.28(W) x 4.23(H) x 1.43(D) inches Approx. 245g/ 8.7oz with EBP-72 & antenna 16 Buttons Keypad
encode/decode 39 tones
encode/decode 104 codes
<TRANSMITTER>
Output power (Approx.):
Modulation Max. deviation
Spurious emission
<RECEIVER>
Receive system
Intermediate frequencies Sensitivity (12dB SINAD) Selectivity
Audio output power
**Narrow FM models are available depending on areas of distribution.
5W (High)/ 2W (Middle)/ 0.5W (Low) Variable reactance frequency modulation
±5KHz
(±2.5KHz)**
-60dB or less
Double conversion superheterodyne
1st: 21.7MHz / 2nd: 450KHz
-14dB|j (0.2jV)
-6dB: 12KHz or more/ -60dB: 26KHz or less (-6dB: 6KHz or more/ -60dB: 14KHz or less)** 500mW (8 Q, MAX) 400mW (8 Q , 10% THD)
CIRCUIT DESCRIPTION
1) Receiver System
The receiver system is a double superheterodyne system with a 21.7MHz first IF and
a 450kHz second IF.
1.Front End
The received signal at frequency in the 136~173.995MHz (E version:
144~145.995MHz) range is passed through the low-pass filter (L101, L102, L104, L118, C101, 108, C109, C110, C117, C118, C119, C123, C124, C125,
C126, C127, and C188) and tuning circuit (C255, C256, C257, C258, D120,
L138, and L139) and amplified by the RF amplifier (Q119). The signal from Q119 is then passed through the tuning circuit (C242, C243, C244, C245, C269, C270, C271, D117, D118, D119, L135, L136, and L137) and converted into 21.7MHz by the mixer (Q118). The tuning circuit, which consists of L139, L135, L136, varicaps D117, D118, D119, and D120 is controlled by the tracking voltage from the CPU so that it is optimized for the reception frequency. The local signal from the VCO is passed through the buffer (Q115), and supplied to the source of the mixer (Q118). The radio uses the lower side of the superheterodyne system.
2. IF Circuit
The mixer mixes the received signal with the local signal to obtain the sum of and difference between them. The crystal filter (FL101, and FL102) selects
21.7MHz frequency from the results and eliminates the signal of the unwanted frequencies. The first IF amplifier (Q121) then amplifies the signal of the selected frequency.
3. Demodulator Circuit
After the signal is amplified by the first IF amplifier (Q121), it is input to pin 16 of the demodulator IC (IC103). The second local signal of 21.25MHz (shared with PLL IC reference oscillation), which is oscillated by the TCXO (X102). Then, these two signals are mixed by the internal mixer in IC103 and the result is converted into the second IF signal with a frequency of 450kHz. The second
IF signal is output from pin 3 of IC103 to the ceramic filter (FL103), where the unwanted frequency band of that signal is eliminated, and the resulting signal is sent back to the IC103 through pin 5. The second IF signal input via pin 5 is demodulated by the internal limiter amplifier and quadrature detection circuit in IC103, and output as an audio signal through pin 9.
4. Audio Circuit
The audio signal from pin 9 of IC103 is amplified by the AF amplifier (Q120). The signal is then input to pin 16 of the electronic volume (IC105) for volume adjustment, and output from pin 14. The adjusted signal is sent to the audio power amplifier (IC104) through pin 2 to drive the speaker.
5. Squelch Circuit
The signal except for the noise component in AF signal of IC103 is cut by the active filter inside IC. The noise component is amplified and rectified, then converted to the DC voltage to output from pin 14 of IC103. The voltage is led to pin 2 of CPU and compared with the setting voltage. The squelch will open if the input voltage is lower than the setting voltage.
2) Transmitter System
1. Modulator Circuit
The audio signal is converted to an electric signal in either the internal or external microphone, and input to the microphone amplifier (IC110). IC110 consists of two operational amplifiers; one amplifier (pins 12, 13, and 14) is composed of pre-emphasis and IDC circuits and the other (pins 5, 6, 7, 8, 9, and 10) is composed of a splatter filter. The maximum frequency deviation is obtained by IC105 and input to the cathode of the varicap of the VCO, to change the electric capacity in the oscillation circuit. This produces the frequency modulation.
2. Power Amplifier Circuit
The transmitted signal is oscillated by the VCO, amplified by the pre-drive amplifier (Q101) and drive amplifier (Q106), and input to the final amplifier (Q105). The signal is then amplified by the final amplifier (Q105) and led to the antenna switch (D101) and low-pass filter (L104, L102, L101, C119, C118, C117, C127, C126, C125, C124, C108, and C101), where un-wanted high harmonic waves are reduced as needed, and the resulting signal is supplied to the antenna.
3. APC Circuit
Part of the transmission power from the low-pass filter is detected by D108, converted to DC, and then amplified by a amplifier (IC101). The output voltage controls the bias voltage from the source of Q105 and Q106 to maintain the transmission power constant.
3) PLL Synthesizer System
1. PLL
The dividing ratio is obtained by sending data from the CPU (IC113) to pin 10 and sending clock pulse to pin 9 of the PLL IC ( IC101 ). The oscillated signal from the VCO is amplified by the buffer (Q116) and input to pin 8 of IC102.
Each programmable divider in IC102 divides the frequency of the input signal by N according to the frequency data, to generate a comparison frequency of 5 or 6.25kHz.
2. Reference Frequency Circuit
The reference frequency appropriate for the channel steps is obtained by dividing the 21.25MHz reference oscillation (X102) by 4250 or 3400, according to the data from the CPU (IC113). When the resulting frequency is 5kHz, channel steps of 5, 10, 15, 20, and 30kHz are used. When it is 6.25kHz, channel steps of 12.5, 25 , and 50kHz are used.
3. Phase Comparator Circuit
The PLL (IC102) uses the reference frequency, 5 or 6.25kHz. The phase comparator in the IC102 compares the phase of the frequency from the VCO with that of the comparison frequency, 5 or 6.25kHz, which is obtained by the internal divider in IC102.
4. PLL Loop Filter Circuit
If a phase difference is found in the phase comparison between the reference frequency and VCO output frequency, the charge pump output (pin 5) of IC102 generates a pulse signal, which is converted to DC voltage by the PLL loop filter and input to the varicap of the VCO unit for oscillation frequency control.
5. VCO Circuit
A Colpitts oscillation circuit driven by Q108 directly oscillates the desires frequency. The frequency control voltage determined in the CPU (IC113) and
PLL circuit is input to the varicaps (D105 and D107). This change the oscillation frequency, which is amplified by the VCO buffer (Q113) and output from the VCO unit.
4) CPU and Peripheral Circuits
1. LCD Display Circuit
The CPU turns ON the LCD via segment and common terminals with 1/4 the duty and 1/3 the bias, at the frame frequency is 112.5Hz.
2. Display Lamp Circuit
When the LAMP key is pressed, “L” is output form pin 67 of CPU ( IC113) to the bases of Q140. Q140 then turn ON and the LEDs (D128 and D129) light.
3. Reset and Backup
When the power form the DC jack or external battery increases from Circuits 0V to 2.5 or more, “ H “ level reset signal is output form the reset IC (IC108) to pin 6 of the CPU (IC113), causing the CPU to reset. The reset signal, however, waits at 100, and does not enter the CPU until the CPU clock (X104) has stabilized.
4. S (Signal) Meter Circuit
The DC potential of pin 12 of IC103 is input to pin 83 of the CPU (IC113), converted from an analog to a digital signal, and displayed as the S-meter signal on the LCD.
5. DTMF Encoder
The CPU (IC113) is equipped with an internal DTMF encoder. The DTMF signal is output from pin 71, through IC112 (Low-pass filter), and then through the microphone amplifier (IC110), and is sent to the varicap of the VCO for modulation. At the same time, the monitoring tone passes through the AF circuit and is output form the speaker.
6. TONE Encoder
The CPU (IC113) is equipped with an internal tone encoder. The tone signal (67.0 to 250.3Hz ) is output from pin 70 of the CPU to the 21.25MHz reference oscillation (X102) of the PLL reference oscillator.
7. DCS Encoder
The CPU (IC113) is equipped with an internal DCS code encoder. The code (023 to 754) is output from pin 70 of the CPU to the 21.25MHz reference oscillation (X102) of the PLL reference oscillator.
8. CTCSS, DCS Decoder
The voice band of the AF output signal from pin 9 of IC103 is cut by sharp active filter IC111 and amplified, then led to pin 80 of CPU. The input signal is compared with the programmed tone frequency code in the CPU. The squelch will open when they match.
9. Clock Shift
In the unlikely event that CPU clock noise is present on a particular operating frequency programmed into the radio, you can shift the CPU clock frequency to avoid the CPU clock-noise. The output signal from pin 8 of the CPU turns on Q127. Then the oscillation frequency of X104 will be shifted about 200 ppm.
Parts List MAIN UNIT
Ref. No. Parts No. Parts name Version C101 CU3535 GRM36B102K50PT C102 CU3535 GRM36B102K50PT C103 CU3519 GRM36CH470J50PT C104 CU3535 GRM36B102K50PT C105 C108 CU3535 GRM36B102K50PT C109 CU3512 GRM36CH120J50PT C110 CU3505 GRM36CH040C50PT C111 C112 CU3520 GRM1552C1H560JD01D C113 CU3535 GRM36B102K50PT C114 CU3503 GRM36CK020C50PT C115 C116 CU3512 GRM36CH120J50PT C117 CU3513 GRM36CH150J50PT C118 CU3513 GRM36CH150J50PT C119 CU3513 GRM36CH150J50PT C120 C122 CU3559 GRM155B30J105KE18D C123 C124 CU3512 GRM36CH120J50PT C125 CU3512 GRM36CH120J50PT C126 CU3513 GRM36CH150J50PT C127 CU3514 GRM36CH180J50PT C129 CU3512 GRM36CH120J50PT C130 CU3514 GRM36CH180J50PT T, E, EUK C131 CU3517 GRM36CH330J50PT C132 CU3516 GRM36CH270J50PT C133 CU3517 GRM36CH330J50PT C134 CU3513 GRM36CH150J50PT C135 CU3513 GRM36CH150J50PT C136 CU3513 GRM36CH150J50PT C137 CU3535 GRM36B102K50PT C138 C139 C140 CU3554 GRM36B104K10PT C141 CU3535 GRM36B102K50PT C142 CU3502 GRM36CK010C50PT C144 C145 CU3535 GRM36B102K50PT C146 CU3535 GRM36B102K50PT C147 CU3506 GRM36CH050C50PT C149 CU3502 GRM36CK010C50PT C150 CU3502 GRM36CK010C50PT C151 CU3547 GRM36B103K16PT C152 CU3535 GRM36B102K50PT C153 C155 CU3535 GRM36B102K50PT C156 C157 CU3535 GRM36B102K50PT C158 CU3535 GRM36B102K50PT C159 CU3547 GRM36B103K16PT C160 CU3535 GRM36B102K50PT C161 CU3535 GRM36B102K50PT C162 C163 CU3535 GRM36B102K50PT C164 CS0441 TMCMA0J226MTRF C165 CU3535 GRM36B102K50PT C166 CU3513 GRM36CH150J50PT C167 CU3523 GRM1552C1H101JZ01D C168 CU3502 GRM36CK010C50PT C169 CU3502 GRM36CK010C50PT C171 CU3511 GRM36CH100D50PT C172 CU3535 GRM36B102K50PT
CU3535 GRM36B102K50PT
Ref. No. Parts No. Parts name C173 C174 C175 C176 CU3502 GRM36CK010C50PT C177 CU3535 GRM36B102K50PT C178 CU3513 GRM36CH150J50PT C179 CU3535 GRM36B102K50PT C180 CU3515 GRM36CH220J50PT C181 CU0119 GRM21BB30J106KE18L C182 CU3554 GRM36B104K10PT C183 CU3535 GRM36B102K50PT C184 CU3547 GRM36B103K16PT C185 CU3535 GRM36B102K50PT C186 C187 CU3513 GRM36CH150J50PT C188 CU3508 1005 CH 50V 7PF D C189 CU3535 GRM36B102K50PT C190 C191 CU3137 GRM188B31C105KA92D C192 CU3535 GRM36B102K50PT C193 CU3514 GRM36CH180J50PT C194 CU3554 GRM36B104K10PT C195 CU3535 GRM36B102K50PT C196 CU3502 GRM36CK010C50PT C197 CU3527 GRM1552C1E221JD01D C198 CU3554 GRM36B104K10PT C199 CU3515 GRM36CH220J50PT C200 CU3554 GRM36B104K10PT C201 CU3535 GRM36B102K50PT C202 CU3547 GRM36B103K16PT C203 CU3535 GRM36B102K50PT C204 CU3535 GRM36B102K50PT C205 CS0396 20V 0.1UF C206 CS0396 20V 0.1UF C207 CU3547 GRM36B103K16PT C209 CU3515 GRM36CH220J50PT T, E, EUK C209 CU3514 GRM36CH180J50PT TFH C210 CU3505 GRM36CH040C50PT C211 CU3526 GRM1552C1E181JD01D C212 CU3528 GRM1552C1E271JD01D C213 CU3526 GRM1552C1E181JD01D C214 CU3535 GRM36B102K50PT C215 CU3554 GRM36B104K10PT C216 C219 CS0398 6.3V 2.2UF C220 CU3535 GRM36B102K50PT C221 CU3535 GRM36B102K50PT C222 CU3535 GRM36B102K50PT C223 C224 CU3547 GRM36B103K16PT C225 CU3535 GRM36B102K50PT C226 CU3535 GRM36B102K50PT C227 CU3535 GRM36B102K50PT C228 CU3515 GRM36CH220J50PT C229 CU3515 GRM36CH220J50PT C230 CU3512 GRM36CH120J50PT C231 CU0119 GRM21BB30J106KE18L C232 CU3535 GRM36B102K50PT C233 CU3522 GRM1552C1H820JD01D C234 CU3547 GRM36B103K16PT C235 CU3519 GRM36CH470J50PT C236 CU3535 GRM36B102K50PT C237 CU3547 GRM36B103K16PT C238 CU3539 GRM36B222K50PT
Ref. No. Parts No. Parts name Version C239 CU3547 GRM36B103K16PT C240 CU3535 GRM36B102K50PT C241 CU3539 GRM36B222K50PT C242 CU3535 GRM36B102K50PT C243 CU3573 GRM1554C1HR80BZ01D C244 CU3573 GRM1554C1HR80BZ01D C245 CU3523 GRM1552C1H101JZ01D C246 CU3554 GRM36B104K10PT C247 CU3554 GRM36B104K10PT C248 CU3559 GRM155B30J105KE18D C249 CU3537 GRM36B152K50PT C250 CU3537 GRM36B152K50PT C252 CU3535 GRM36B102K50PT C253 CU3543 GRM36B472K25PT C254 CU3549 1005 B 16V 0.015UF K C255 CU3535 GRM36B102K50PT C256 CU3516 GRM36CH270J50PT C257 CU3505 GRM36CH040C50PT C258 CU3523 GRM1552C1H101JZ01D C259 C260 CU3554 GRM36B104K10PT C261 CU3547 GRM36B103K16PT C262 CU3535 GRM36B102K50PT C263 CU3508 1005 CH 50V 7PF D T, E, TFH C263 CU3513 GRM36CH150J50PT EUK C264 CU3535 GRM36B102K50PT C265 CE0436 16CE47BSS C266 CU3137 GRM188B31C105KA92D C267 CU3535 GRM36B102K50PT C268 CU3535 GRM36B102K50PT C269 CU3523 GRM1552C1H101JZ01D C270 CU3523 GRM1552C1H101JZ01D C271 CU3523 GRM1552C1H101JZ01D C272 CU3535 GRM36B102K50PT C273 CU3547 GRM36B103K16PT C274 CU3554 GRM36B104K10PT C275 CU3535 GRM36B102K50PT C276 CU3523 GRM1552C1H101JZ01D C277 CU3535 GRM36B102K50PT C278 CU3523 GRM1552C1H101JZ01D C279 CU3547 GRM36B103K16PT C280 CS0441 TMCMA0J226MTRF C281 CU3535 GRM36B102K50PT C282 CU3554 GRM36B104K10PT C284 CU3559 GRM155B30J105KE18D C285 CU3554 GRM36B104K10PT C286 CU3527 GRM1552C1E221JD01D C287 CU3535 GRM36B102K50PT C288 CU3527 GRM1552C1E221JD01D C289 CU3535 GRM36B102K50PT C290 CU3554 GRM36B104K10PT C291 CU3138 GRM188B31C225KE14D C292 CE0436 16CE47BSS C293 CU3554 GRM36B104K10PT C294 CU3535 GRM36B102K50PT C295 C296 CE0463 10CE100BSS C297 C298 CU3535 GRM36B102K50PT C299 CU3137 GRM188B31C105KA92D C300 CU3554 GRM36B104K10PT C301 CU3535 GRM36B102K50PT C302 CE0462 6CE100BSS C303 CU3535 GRM36B102K50PT C304 CU3554 GRM36B104K10PT
Ref. No. Parts No. Parts name C305 CU3138 GRM188B31C225KE14D T, E, EUK C306 CU3559 GRM155B30J105KE18D C307 CU3535 GRM36B102K50PT C308 CU3138 GRM188B31C225KE14D C310 CU3137 GRM188B31C105KA92D C311 CU3535 GRM36B102K50PT C312 CU3554 GRM36B104K10PT T, E, EUK C313 CU3137 GRM188B31C105KA92D C314 CU3547 GRM36B103K16PT C315 CU3547 GRM36B103K16PT C316 CU3554 GRM36B104K10PT C317 CU3517 GRM36CH330J50PT C318 CU3516 GRM36CH270J50PT C319 C320 CU3535 GRM36B102K50PT C321 CU3535 GRM36B102K50PT C322 CU3559 GRM155B30J105KE18D C323 CU3535 GRM36B102K50PT C324 CU3559 GRM155B30J105KE18D C325 CU3554 GRM36B104K10PT C326 C327 CU3137 GRM188B31C105KA92D C328 CU3535 GRM36B102K50PT C329 CU3554 GRM36B104K10PT C330 CU3535 GRM36B102K50PT C331 CU0119 GRM21BB30J106KE18L C332 CU3535 GRM36B102K50PT C333 CU3535 GRM36B102K50PT C334 CU0119 GRM21BB30J106KE18L C335 CU3540 GRM36B272K50PT C336 CU3523 GRM1552C1H101JZ01D C337 CU3535 GRM36B102K50PT C338 CU3137 GRM188B31C105KA92D C339 CU3137 GRM188B31C105KA92D C340 CU3535 GRM36B102K50PT C341 CU3547 GRM36B103K16PT C342 CU3547 GRM36B103K16PT C343 CU3554 GRM36B104K10PT C344 CU3554 GRM36B104K10PT C345 CU3554 GRM36B104K10PT C346 CU3547 GRM36B103K16PT C347 CU3523 GRM1552C1H101JZ01D C348 CU3547 GRM36B103K16PT C349 CU3539 GRM36B222K50PT C350 CU3533 GRM36B681K50PT C351 C352 CU3547 GRM36B103K16PT C353 CU3539 GRM36B222K50PT C354 CU3541 GRM36B332K50PT C355 CU3547 GRM36B103K16PT C356 CU3535 GRM36B102K50PT C357 CU3535 GRM36B102K50PT C358 CU0119 GRM21BB30J106KE18L C359 CU3553 GRM36B473K10PT C360 CU3559 GRM155B30J105KE18D C361 CU3535 GRM36B102K50PT C362 CU3533 GRM36B681K50PT C363 CU3535 GRM36B102K50PT C364 CU3539 GRM36B222K50PT C365 CU3533 GRM36B681K50PT C366 CU3537 GRM36B152K50PT C367 CU3523 GRM1552C1H101JZ01D C368 CU3531 GRM36B471K50PT C369 CU3541 GRM36B332K50PT C370 CU3554 GRM36B104K10PT
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