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Luiton LT-308 Service Manual

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LT-308
SERVICE MANUAL

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Summary of Contents for Luiton LT-308

  • Page 1 LT-308 SERVICE MANUAL...
  • Page 2 -TECNNICAL CHARACTERITICS 1-GENERAL: -Multiconfiguration(D,EU,EC,UK,PL,E,US,NZ) -D ⇒ 80 channels FM 4W (from 26.565Mhz to 27.405Mhz) -EU ⇒ 40 channels FM 4W/AM 1W (from 26.965Mhz to 27.405Mhz) -EC ⇒ 40 channels FM 4W (from 26.965Mhz to 27.405Mhz) -U ⇒ 40 channels FM 4W (from 26.965Mhz to 27.405Mhz) -PL ⇒...
  • Page 3 3-RECEPTION: -Maximum sensitivity at 20dB sinad -0,5µV(-113dBm) AM/FM -Audio frequency response -From 300Hz to 3kHz in AM/FM -Adjacent channel selectivity -Superior to 60dB -Frequency image rejection -Superior to 60dB -Intermodulation response -Superior to 54dB -Maximum audio power -Squelch sensitivity -Threshold 0,2µV(-120dBm)/Tight 1mV(-47dBm) -Current drain -500mA nominal/800mA maximum...
  • Page 4 ALIGNMENT PROCEDURE LUTION LT-308 * VCO/PLL PORTION - Alignment procedure - Test points - Frequencies chart * TRANSMITTER - Alignment procedure - Test points * RECEIVER - Alignment procedure - Test points Test equipement required Frequency counter 200 Mhz HF Generator...
  • Page 5 ALIGNMENT VCO/PLL 1 - Alignment procedure(13,2V;configuration“PL”) STEP CONDITION ADJUSTMENT REMARKS OF ADJUSTMENT FM(PL) Connecting a voltmeter to test TX mode TP6,to reach 2.2V±0,2V. Channel 19 FM(PL) Connecting a voltmeter to test RX mode TP6,to reach 2.2V±0,2V Channel 19 FM(PL) TX/ Connect a voltmeter to TP6,and check: RX mode Rx Channel 1=1.8V±0,2V...
  • Page 6 - FREQUENCY LIST (PL) Channels Frequencies Frequencies (MHz) (MHz) 26,960 37,660 26,970 37,670 26,980 37,680 27,000 37,700 27,010 37,710 27,020 37,720 27,030 37,730 27,050 37,750 27,060 37,760 27,070 37,770 27,080 37,780 27,100 37,800 27,110 37,810 27,120 37,820 27,130 37,830 27,150 37,850 27,160 37,860...
  • Page 7 - FREQUENCY LIST (EC,E1,EU,US) Channels Frequencies Frequencies (MHz) (MHz) 26,965 37,655 26,975 37,665 26,985 37,675 27,005 37,695 27,015 37,705 27,025 37,715 27,035 37,725 27,055 37,745 27,065 37,755 27,075 37,765 27,085 37,775 27,105 37,795 27,115 37,805 27,125 37,815 27,135 37,825 27,155 37,845 27,165 37,855...
  • Page 8 - FREQUENCY LIST (NZ) Channels CEPT Frequencies Frequencies (MHz) (MHz) 26,330 37,030 26,340 37,040 26,350 37,050 26,370 37,070 26,380 37,080 26,390 37,090 26,400 37,100 26,420 37,120 26,430 37,130 26,440 37,140 26,450 37,150 26,470 37,170 26,480 37,180 26,490 37,190 26,500 37,200 26,520 37,220 26,530...
  • Page 9 - FREQUENCY LIST (U) Channels Frequencies Frequencies (MHz) (MHz) 27,60125 38,30125 27,61125 38,31125 27,62125 38,32125 27,63125 38,33125 27,64125 38,34125 27,65125 38,35125 27,66125 38,36125 27,67125 38,37125 27,68125 38,38125 27,69125 38,39125 27,70125 38,40125 27,71125 38,41125 27,72125 38,42125 27,73125 38,43125 27,74125 38,44125 27,75125 38,45125 27,76125 38,46125...
  • Page 10 - FREQUENCY LIST (d) Channels Channels Frequencies Frequencies Frequencies Frequencies (MHz) (MHz) (MHz) (MHz) 26,965 37,665 26,565 37,265 26,975 37,675 26,575 37,275 26,985 37,685 26,585 37,285 27,005 37,055 26,595 37,295 27,015 37,715 26,605 37,305 27,025 37,725 26,615 37,315 27,035 37,735 26,625 37,325 27,055...
  • Page 11 ALIGNMENT TRANSMITTER 1 - Alignment procedure(13,2V;configuration”PL,EU”) STEP CONDITION ADJUSTMENT REMARKS OF ADJUSTMENT VR2(LOW) AM(EU) Connect a wattmeter to jack antenna, adjust VR2 to reach 1W on Channel 20 the wattmeter. VR1(HI) FM(PL) Connect a wattmeter to jack antenna, adjust VR1 to reach 4W on Channel 20 the wattmeter.
  • Page 12 ALIGNMENT RECEIVER 1 - Alignment procedure(13,2V;configuration”PL”) STEP CONDITION ADJUSTMENT REMARKS OF ADJUSTMENT T1-T2-T3 AM(PL) Channel Connect HF generator to jack antenna T4-T5 20 Middle adjusted at ( –107dBm 1KHz 60%), volume level. connect sinad meter to jack EXT speaker No squelch active and adjust coils for maximum sensitivity( ≥...
  • Page 13 Circuit brief AM reception channels:  This  27M  received  signal  is  input  through  a  high‐pass  filter  after  the  transceiver switching diode D15,4 through T5 high level after adjusting the  frequency selection transistor Q24, T4, T2. Into the mixer circuit Q13, Q12,  T1. At the same time the local oscillator VCO shock Q4 signal to the D2, T1,  generating an intermediate frequency signal 10.7MHZ, after FT3 input U3  16PIN evacuation second intermediate 450K through Q21, Q19, enter the  AM frequency discriminator weeks T3.  FM Receive Channel:  This  27M  received  signal  is  input  through  a  high‐pass  filter  after  the  transceiver switching diode D15,4 through T5 high level after adjusting the  frequency selection transistor Q24, T4, T2. Into the mixer circuit Q13, Q12,  T1. At the same time the local oscillator VCO shock Q4 signal to the D2, T1,  generating an intermediate frequency signal 10.7MHZ, after FT3 input U3  16PIN VCO second local oscillation signal transmitted by the U1 PIN9 U3  PIN1.  AM Audio output: ...
  • Page 14 This is the U3 PIN9 FM audio output through D7, Q22 transceiver into the  switch by the U5 13PIN after U5 14PIN output amplification sent through  Q37 transceiver volume potentiometer switch into U9 PIN1, the U9 PIN4  zoom through C191, T6, C205, J3 Biography to speakers.  PLL:  VCO  by  the U2PIN25, PIN26,  PIN28 send data signals to U1 PIN6, PIN7,  PIN8, U1 frequency input from the X1 U1PIN10, PIN11, by the U1PIN1 sent  by  the  Q4  output  local  oscillator  signal  to  the  receiving  circuit,  the  Q8  output to transmit channels.  Transmit signals:  VCO frequency vibration generated through Q9, Q8 Q5 transported to the  first stage and amplified by the power transistor Q1 driven sent to Q10,  the signal sent through a high‐pass filter by the antenna.  AM modulation:  This voice signal input through the MIC VR6, Q40, Q31, Q38Q39 into U9  PIN1, the U9 PIN4 zoom out.  FM modulation:  This voice signal input through the MIC input U4 PIN5 PIN7 zoom through  D11 U4 PIN3 Q26 Q17 After adjusting VR3 into VCO modulation. ...

  • Page 15: Component Layout

    LUITON LT-308 COMPONENT LAYOUT...
  • Page 18 LUITON LT-298 BLOCK DIAGRAM...
  • Page 19 ASQ DET 1ST MIX RF ATT AF AMP AM DET AF AMP AF PWR Q13 Q12 FM DET AGC AMP RSSI RF GAIN BAND L8 L10 Q21 Q22 L11 L14 SQ VOL SQ CONT Q29 Q27 Q25 FINAL SP SW RX METU DRIVE BUFFER...
  • Page 20 LUITON LT-298 SCHEMATIC DIAGRAM...
  • Page 21 C146 102P R126 100K R120 C130 R127 R139 R117 180K 200K FM AFOUT C147 RSSI 100K C145 RSSI 2UF2/16V C134 103P 104P R121 RB706F C164 C163 100K 270R DTC114ECA 103P 104P V_RF1 R108 220K LM2902 V_RF1 V_TX C133 V_TX 105P C123 3361D01 100P...
  • Page 22 LCD800 LCD-CB508 U800 TM1722 RV800 V-MCU J809 J-CB-6P R811 R804 D802 V-MCU R826 R827 R828 R805 C804 C805 D803 R806 104P 106P D800 R807 D801 DOWN R800 R801 D804 R0603 R0603 K800 V-MCU R810 R803 100R K801 C801 C802 C803 C800 220P 220P...
  • Page 26 LUITON LT-298 BOMPONENTS LIST...
  • Page 27 Description / Specifications Remark PCB HE-308(V22) Double plate, thickness 1.6mm HASL process size: 114 * 139mm Chip Resistors 0603 0Ω 5% 1/10W RoHS R26, R49, R154, R155 Chip Resistors 0603 2R2 5% 1/10W RoHS R34, Chip Resistors 0805 0Ω 5% 1/8W RoHS Chip Resistors 0603 10Ω...
  • Page 28 Chip Resistors 0603 33kΩ 5% 1/10W RoHS R90, R110, R116, R141, R142, R143,R140 Chip Resistors 0603 39kΩ 5% 1/10W RoHS Chip Resistors 0603 390kΩ 5% 1/10W RoHS R86 Chip Resistors 0603 47Ω 5% 1/10W RoHS R60, R100, R105, R134 Chip Resistors 0603 470Ω 5% 1/10W RoHS R33, R167,R55,R123,R41,R202, Chip Resistors 0603 4.7kΩ...
  • Page 29 Chip capacitors 0603 15p±5% RoHS C130,C98, Chip capacitors 0805 152p±10% RoHS Chip capacitors 0805 180p±10% RoHS Chip capacitors 0603 20p±5% RoHS Chip capacitors 0603 22p±5% RoHS C66, C97, C137,C30 Chip capacitors 0805 220p±10% RoHS C125 Chip capacitors 0603 222p±10% RoHS C190 Chip capacitors 0603 223p±10% RoHS C27, C41, C42, C82, C88, C95, C106, C138, C142, C179, C183, C199, C209, C211, C 15...
  • Page 30 Chip capacitors 0603 682p±10% RoHS Chip capacitors 0603 7p±0.25p RoHS Chip capacitors 0603 82p±5% RoHS Chip capacitors 0603 820p±10% RoHS Chip capacitors 0603 822±10% RoHS C111 Chip capacitors 1206 1uF/16V ±10% RoHS C14, Chip capacitors 1206 10uF/16V RoHS Chip inductance 0805 101 ±25% RoHS Chip inductance 0603 120nH ±5% RoHS Chip inductance 0603 221 ±25% 1A RoHS L12, L13, L15, L16...
  • Page 31 112 Chip triode S9018L SOT23 RoHS Q2, Q4, Q8, Q9, Q7, 113 Chip triode 2SC1623（L6） SOT23 RoHS Q25, Q26, Q27, Q29 114 Chip triode 2SC2712（LY） SOT23 RoHS Q12, Q13, Q19, Q21, Q23, Q24, 115 Chip triode SS8550 SOT23 RoHS Q15, Q16, Q30, Q35 116 ntegrated circuit 3361D01 SOP16 RoHS 117 ntegrated circuit ICMCD2926 SSOP16 RoHS 118 ntegrated circuit NJM2902V-TE2 SSOP14 RoHS U5...
  • Page 32 140 Plug-ntegrated circuit TDA2003 TO-220B ROHS U5 141 Plug-inductance HE308 03# 7X7 非 RoHS 142 Plug-inductance HE308 04# 7X7 非 RoHS 143 Plug-inductance HE308 RA 7X7 非 RoHS 144 Plug-inductance HE308 RB 7X7 非 RoHS 145 Plug-inductance HE308 5# 7X7 非 RoHS 146 Plug-crystal 10.25M RoHS 147 plug-Crystal filter 10.7MHZ （±3.75KHZ/3dB）RFT3 148 plug-filter LTW450HT RoHS...
  • Page 33 168 Chip Resistors 0603 47kΩ 5% 1/10W RoHS R812,R813 169 Chip Resistors 0603 100kΩ 5% 1/10W RoHs R814,R815,R820 170 Chip capacitors 0603 220p±5% RoHS C801,C802,C803 171 Chip capacitors 0603 102p±10% RoHS C800, 172 Chip capacitors 0603 104p±10% RoHS C804 173 Chip inductance 1206 301 ±25% RoHS C805 174 Chip inductance 0603 101 ±25% RoHS R810...
  • Page 34 191 RF Connectors SL16-KY ROHS 192 line UL2468-18AWG long:270mm ROHS 193 LT308 panel ABS ROHS 194 LT308 panel buttons ABS ROHS 195 LT308 Panel SQ / RF Knob ABS ROHS 196 LT308 panel VOL knob ABS ROHS 197 LT308308 panel LED mirror ROHS 198 Power clip buckle 2P-4 ROHS 199 Insulating spacer White ROHS...
  • Page 35 LT308 front of the microphone button art silk screen ROHS LT308 front of the microphone button is not printing ROHS 241 Self-tapping screws ST2.5X5.5 半 ROHS End product LUITON LT-308 frequencyEU （26.965-27.405MHz）/CE 40CH Semifinished product LT-308 frequencyEU （26.965-27.405MHz）/CE 40CH 244 LUITON LT-308 English box...
  • Page 36 245 LUITON LT-308 English manual 246 LT308 microphone in hand within a paper card 247 LT308 hosts in the paper card 248 transparent bag 30 X 15.5 CM 249 transparent bag 9 X 6CM 250 transparent bag 18.5X 8.5CM fuse 2A250V R6 X 30mm 252 Cigarette lighter cable UL2468-18AWG Rubber gasket 23(outer path)*7.5（Inside...