Maxon SD-125E Service Manual
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Maxon SD-125E Service Manual

Rf link module
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SD-125E
SERVICE
MANUAL
MaxonCIC Corp. Chongho Bldg, #7-61, Yangjae-Dong, Seocho-Ku, Seoul, 137-130, Korea
Phone: (82) 2 3498 - 3114; Fax: (82) 2 3498 -3113
October 2008

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  • Page 1 SD-125E SERVICE MANUAL MaxonCIC Corp. Chongho Bldg, #7-61, Yangjae-Dong, Seocho-Ku, Seoul, 137-130, Korea Phone: (82) 2 3498 - 3114; Fax: (82) 2 3498 -3113 October 2008...

  • Page 2: Table Of Contents

    MAXONCIC SD-125E RF LINK MODULE 1. TABLE OF CONTENTS 2. SPECIFICATIONS 3. UNPACKING 4. INTRODUCTION 5. FEATURES 6. THEORY OF OPERATION 6.1 INTRODUCTION 6.2 DIGITAL CIRCUITS 6.3 RF CIRCUITS 6.4 RF CIRCUITS PLL SYNTHESIZER 6.5 RECEIVER 7. MAINTENANCE AND REPAIR 7.1 GENERAL...
  • Page 3 MAXONCIC SD-125E RF LINK MODULE 17.9 DIGITAL BOARD(148-174MHz)SCHEMATIC 17.10 RF BOARD VHF PRINTED CIRCUIT BOARDS 17.11 RF BOARD UHF PRINTED CIRCUIT BOARDS 17.12 DIGITAL BOARD PRINTED CIRCUIT BOARDS 18. EXPLODED VIEW & PARTS LIST - 3 -...

  • Page 4: Specifications

    MAXONCIC SD-125E RF LINK MODULE GENERAL Equipment Type ……………………………………………………… Data radio Performance Specifications………………………………………… TIA/EIA -603 / IC, RSS212 Band …………………………………………………………………… VHF(SD-125VEV2) / UHF(SD-125VEU) Channel Spacings …………………………………………………… 25 kHz, 12.5 kHz programmable RF Output Power …………………………………………………… 1 watt, 5 watt programmable Modulation Type ……………………………………………………...
  • Page 5 MAXONCIC SD-125E RF LINK MODULE TRANSMITTER Specification Carrier Power: ………………………………………………………… Nom. Max. Min. Hi ………………………………………………………………………5W < 6W > 4.5W Low ……………………………………………………………………1W < 1.5W > 0.8W Sustained Transmission …………………………………………… Nominal conditions Time : 5 30 Sec. Power: >90% >85% >80% Frequency Error ………………………………………………………< 0.5 kHz Nominal condition for VHF <...
  • Page 6 MAXONCIC SD-125E RF LINK MODULE RECEIVER Specification Sensitivity (12dB Sinad) …………………………………………… Standard B.W < -117 dBm, Narrow B.W <-118 dBm @ Nom. Condition Standard B.W < -115 dBm, Narrow B.W <-116 dBm @ Extreme Condition Amplitude Characteristic....... . < ±3 dB Adjacent Channel Selectivity: 25 kHz Channel Spacing ……………………………………………...
  • Page 7 MAXONCIC SD-125E RF LINK MODULE Environmental (performance without degradation unless stated) Temperature…………………………………………………………deg C Operating ……………………………………………………………-30℃ to +60℃ Degradation Specified @Extreme Storage……………………………………………………………….-40℃ to +80℃ Recharging …………………………………………………………..-10℃ to+55 ℃ ESD ………………………………………………………………….. 20kV (C-MIC≥15KV) Vibration ………………………………………………………………MIL STD 810 C Procedures Ⅰ,Ⅱ,Ⅴand IEC68 26 PROGRAMMER …………...

  • Page 8: Unpacking

    MAXONCIC SD-125E RF LINK MODULE The SD-125 RF Link Module is the only item included in the shipping container. - 8 -...
  • Page 9 1997, has adopted a safety standard for human exposure to Radio Frequency (RF) electromagnetic energy emitted by FCC requlated equipment. Maxon subscribes to the same safety standard for the use of its products. Proper operation of this radio will result in user exposure far below the Occupational Safety and Health Act (OSHA) and Federal Communications Commission limits.
  • Page 10 MAXONCIC SD-125E RF LINK MODULE Busy Channel Lockout 16 Channels TX Time-out Power Save 1 / 5 Watt Programmable Output 12.5 / 25 kHz Programmable Channel Spacing Busy Channel Lockout The Busy Channel Lockout feature, when enabled, disables the transmitter when the receiving channel is busy and the user attempts to transmit.

  • Page 11: Introduction

    MAXONCIC SD-125E RF LINK MODULE 6.1 INTRODUCTION The VHF and UHF radios are comprised of two PCB's (an RF PCB and a digital PCB). These boards are connected with an 18 pin female and male connector . The digital board is interfaced with external data equipment through the 9 pin d-sub male connector, which controls the radio and data receiving and sending .

  • Page 12: Rf Circuits

    MAXONCIC SD-125E RF LINK MODULE 6.3 RF CIRCUITS TRANSMITTER The transmitter is comprised of: Buffer P.A. Module Low Pass Filter Antenna Switch A.P.C. Circuits BUFFER VCO output level is -6dBm and amplified to +10dBm (UHF), +6dBm (VHF). The buffer consists of Q8 and Q9 for isolation and gain.

  • Page 13: Rf Circuits Pll Synthesizer

    MAXONCIC SD-125E RF LINK MODULE 6.4 RF CIRCUITS PLL SYNTHESIZER 12.8 MHz TCXO The TCXO contains the 3-stage thermistor network compensation and crystal oscillator and modulation ports. Compensation is ±5 PPM or less from -30c to +60c. PLL IC DUAL MODULES PRESCALER Input frequency of 12.8 MHz to Pin 1 of IC2 MB15E03SL is divided to 6.25 kHz or 5 kHz or 2.5KHz by the...

  • Page 14: Receiver

    MAXONCIC SD-125E RF LINK MODULE 6.5 RECEIVER FRONT-END The receive signal is routed backward through the low pass filter, then onward to C601 of the Hybrid Receiver Front End Module to a bandpass filter consisting of (VHF C622 through C608, L607 through L604 ) and (UHF C601through C610, L601 through L603 ) is coupled to the base of Q601 which serves as an RF amplifier.
  • Page 15 MAXONCIC SD-125E RF LINK MODULE FIRST MIXER Q16, L15 and C77 are Dual gate FET mixers which provide the 45.1 MHz intermediate frequency output. The filtered frequency from the front end module is coupled to C131 The 45.1 MHz IF output is matched to the input of the 2-pole monolithic filter by C65 and C66.

  • Page 16: Maintenance And Repair

    28 in conjunction with the following procedures: • WARNING: Disconnect the SD-125E from all external equipment at the D-Sub connector prior to disassembly. 7.2 REMOVING & REPLACING THE UPPER COVER Removing the Upper Cover: Unscrew the four upper cover mounting screws located on the upper cover of the radio.

  • Page 17: Removing & Replacing The Digitalboard & Shield Plate

    MAXONCIC SD-125E RF LINK MODULE 7.3 REMOVING & REPLACING THE DIGITAL BOARD & SHIELD PLATE Removing the Digital Board Assembly & Shield Plate: Remove the Upper Cover (refer to Removing & Replacing the Upper Cover). Disconnect the DB9 pin connector on CON401.

  • Page 18: Removing & Replacing The Rf Board

    MAXONCIC SD-125E RF LINK MODULE Figure 3-Shield Plate Removal 7.4 REMOVING & REPLACING THE RF BOARD Removing the RF Board Assembly: Remove the Upper Cover (refer to Removing & Replacing the Upper Cover). Remove the Digital Board Assembly and Shield Plate (refer to Removing &...
  • Page 19 MAXONCIC SD-125E RF LINK MODULE Reverse the steps taken to remove the RF Board Assembly. Figure 4-Rf Board removal - 19 -...

  • Page 20: Programming

    VDC 200mA Power Supply. Refer to the ACC-900E Programming User’s Manual for detailed information on programming the SD-125E Series radio. The SD-125E UHF/VHF Receiver is by design, broad band covering UHF(400-430 MHz & 440-470 MHz &470-490 MHz) and VHF(148-174 MHz) and should require no special alignment, unless repairs are performed on the receiver portion.
  • Page 21 MAXONCIC SD-125E RF LINK MODULE TX VCO Set the unit to the highest receive frequency 430MHz(UHF1), 470MHz(UHF2), 490MHz(UFH3), 174MHz(VHF) and verify the VCO control voltage is under 9.0 Volts. If it’s over 9.0 Volts, adjust C308 of RX VCO to 9.0 Volts Set the unit to the lowest receive frequency 400MHz(UHF2), 440MHz(UHF2), 470MHz(UFH3), 148MHz(VHF) and verify that the VCO voltage is above 2.0 Volts.
  • Page 22 Maxon’s wide range of data radio products since the crystal control module (DM-0500 series) had their squelch level setting by hardware touch up. With the SD-125E series, the squelch level to open or close (unmute or mute) is set up by software control.

  • Page 23: Test Equipment Setup

    MAXONCIC SD-125E RF LINK MODULE - 23 -...

  • Page 24: Alignment Points Diagram

    MAXONCIC SD-125E RF LINK MODULE RF BOARD DIGITAL BOARD ALIGNMENT POINTS ALIGNMENT POINTS SW401 CHANNEL SELECT SWITCH - 24 -...
  • Page 25 MAXONCIC SD-125E RF LINK MODULE Surface Mount Components Surface mount components should always be replaced using a temperature controlled soldering system. The soldering tools may be either a temperature controlled soldering iron or a temperature controlled hot-air soldering station. A hot-air system is recommended for the removal of components on these boards. With either soldering system, a temperature of 700°...

  • Page 26: Component Replacement

    MAXONCIC SD-125E RF LINK MODULE Surface Mount Component Replacement “Tin” one terminal end of the new component and the corresponding pad of the PCB. Use as little solder as possible. Place the component on the PCB pads, observing proper polarity for capacitors, diodes, transistors, etc.

  • Page 27: Troubleshooting Guide

    MAXONCIC SD-125E RF LINK MODULE SYMPTOMS CAUSES COUNTERMEASURES 1. Incomplete connection 1. Check CON401 connection 2. Defective DC/DC VCC 2. Check IC801 Unit does not work 3. 5v voltage source 3. IC1 (5v ±0.2v) 4. PLL error 4. Check VTCXO/VCO/PLL IC 5.

  • Page 28: Wiring Diagram

    MAXONCIC SD-125E RF LINK MODULE Pin1..Audio In (Data RX) Pin2..Audio Out (Data TX) Pin3..PTT Pin4..GND (Ground) Pin5..B+ (8-18 Volts DC) Pin6..Carrier Detect (Squelch) Pin7..N/C No Connect Pin8..Switch D-SUB 9 CONNECTOR (P/N : 501-394001BA) SD125E RF BOARD P.C.B.

  • Page 29: Component Pinout

    MAXONCIC SD-125E RF LINK MODULE COMPONENT PINOUT MANUFACTURER’S BASE DIAGRAM REFERENCE NO. SYMBOL PART NUMBER AT-41532 Q601 KTC4075 Q3.4.901.902.903.904 2SC5086-Y Q201.202.301.302 KTA2014 Q5.6.905 PBR951 Q10.701 BFR92A Q7.17.19 KTC3875S Q8.12.15.20 KTA1504S Q407 Q13.14.18.21.22.24 KRC104S (ND) 404.406.408 KRA104S (PD) Q7.23.401.402.403.405 KRA110S (PK) Q1.Q2...
  • Page 30 MAXONCIC SD-125E RF LINK MODULE 1SV229 1SV217 D201.202.301 KDS160 D801 UPP9401 D3.D5 KIA7042AF U408 SI4412DY Q801.802 BLT50 Q702 3SK324UG UPD78F0513 U401 MB15E03SL PLL IC TA31136FN IF IC NJM12903V Comparator NJM12904V IC3.4.5 OP AMP - 30 -...
  • Page 31 MAXONCIC SD-125E RF LINK MODULE LTC1435CS IC801 MC14066BD U404 Analog S/W IC OP AMP KIA324F U405.406.409 COMPANDER Quad Voltage LM339 U403 COMPARATOR AT93C56-10SI U402 EEPROM LM386MX U407 AUDIO AMP TK71750SCL TK71733SCL VOLTAGE REGULATOR IC 2SK3476 Silicon N-Channel 1(Gate) Q703 MOS TYPE...
  • Page 47 45.1MHz, 45N15B4 929-300045NC LTWM455HT(2.832.689) 929-310455HTAC SILICONE RUBBER HS50 GRAY 833-501042AA LTM455FW(2.832.685) 929-310455FWAC SD-125E U1 PARTS LIST SD-125E U1(400MHz~430MHz) DIGITAL BOARD(932-558193AA) PARTS LIST DC TO DC CONVERSION ASSY (501-902128AA) Reference No Description Code No Reference No Description Code No R801 1/16W 5% 1608...
  • Page 48 MAXONCIC SD-125E RF LINK MODULE SD-125E U1(400MHz~430MHz) DIGITAL BOARD(932-558193AA) PARTS LIST DIGITAL PCB SMD ASSY (501-402128AB) Reference No Description Code No Reference No Description Code No R134.135.471 1/16W 1608 911-600007BG C411 0.0015UF CM105X7R152K50V 913-421503HHAA R472.473.485 1/16W 1608 911-600007BG C406.420.451 0.01UF...
  • Page 49 MAXONCIC SD-125E RF LINK MODULE SD-125E U1(400MHz~430MHz) RF BOARD(932-558195AB) PARTS LIST FRONT END U1 BAND ASSY (501-372128AA) Reference No Description Code No Reference No Description Code No R(C607.C603) 1/16W 1005 911-600007BF C609.617 12PF GRM36COG120J50V 913-411201HG R(C604,C605) 1/16W 1005 911-600007BF C619...
  • Page 50 MAXONCIC SD-125E RF LINK MODULE SD-125E U1(400MHz~430MHz) RF BOARD(932-558195AB) PARTS LIST RF CIRCUIT ASSY (501-382128AA) R5.6.70 1/16W 1005 911-651027BF 0.33UF 63V 5% 914-333305JG 1/16W 1005 911-651057BF 2.7PF GRM40COG2R7C50V 913-432700HB 1/16W 5% T 1005 911-656037BF GRM40COG060D50V 913-436000HC R9.29.83.96.104 5.6K 1/16W 1005...
  • Page 51 MAXONCIC SD-125E RF LINK MODULE SD-125E U2 PARTS LIST SD-125E U2(440MHz~470MHz) DIGITAL BOARD(932-558193AA) PARTS LIST DC TO DC CONVERSION ASSY (501-902122AA) Reference No Description Code No Reference No Description Code No R801 10K 1/16W 5% 1608 911-610057BG C810 0.01UF GRM39X7R103K25V...
  • Page 52 MAXONCIC SD-125E RF LINK MODULE SD-125E U2(440MHz~470MHz) RF BOARD(932-558195AB) PARTS LIST PWR MODULE U2 ASSY (501-902122AC) Reference No Description Code No Reference No Description Code No R705 10K 1/16W 5% 1608 911-610057BG C711 0.001UF GRM40 X7R102K 50V 913-431003HH R706 1/16W 5% T 1005...
  • Page 53 MAXONCIC SD-125E RF LINK MODULE SD-125E U2(440MHz~470MHz) RF BOARD(932-558195AB) PARTS LIST RF CIRCUIT ASSY (501-382122AA) Reference No Description Code No Reference No Description Code No R27.31.56 1/16W 1005 911-622037BF C42,43,44,48.50 470PF GRM36X7R471K50V 913-414702HH R54.74 2.2K 1/16W 5% T 1005 911-622047BF C53.55.56.57.58...
  • Page 54 MAXONCIC SD-125E RF LINK MODULE SD-125E U2(440MHz~470MHz) RF BOARD(932-558184AB) PARTS LIST TX VCO U2 BAND ASSY (501-362122AB) R201 1/16W 1005 911-600007BF C214 0.001UF GRM36X7R102K50V 913-411003HH R202 1/16W 5% T 1005 911-610037BF C206 0.5PF GRM36COG0R5C50V 913-410500HBAA R203 100K 1/16W 5% T 1005...
  • Page 55 MAXONCIC SD-125E RF LINK MODULE SD-125E U3 PARTS LIST SD-125E U3(470MHz~490MHz) DIGITAL BOARD(932-558193AA) PARTS LIST DC TO DC CONVERSION ASSY (501-902129AA) Reference No Description Code No Reference No Description Code No R801 10K 1/16W 5% 1608 911-610057BG C810 0.01UF GRM39X7R103K25V...
  • Page 56 MAXONCIC SD-125E RF LINK MODULE SD-125E U3(470MHz~490MHz) RF BOARD(932-558195AB) PARTS LIST PWR MODULE U2 ASSY (501-902129AE) Reference No Description Code No Reference No Description Code No R705 10K 1/16W 5% 1608 911-610057BG C711 0.001UF GRM40 X7R102K 50V 913-431003HH R706 1/16W 5% T 1005...
  • Page 57 MAXONCIC SD-125E RF LINK MODULE SD-125E U3(470MHz~490MHz) RF BOARD(932-558195AB) PARTS LIST RF CIRCUIT ASSY (501-382129AA) Reference No Description Code No Reference No Description Code No R27.31.56 1/16W 1005 911-622037BF C34.40 470PF GRM40COG471J50V 913-434702HG R54.74 2.2K 1/16W 5% T 1005 911-622047BF...
  • Page 58 MAXONCIC SD-125E RF LINK MODULE SD-125E U3(470MHz~490MHz) RF BOARD(932-558184AB) PARTS LIST TX VCO U2 BAND ASSY (501-362129AB) Reference Description Code No Reference No Description Code No R201 1/16W 1005 911-600007BF C214 0.001UF GRM36X7R102K50V 913-411003HH R202 1/16W 5% T 1005 911-610037BF C204.206...
  • Page 59 MAXONCIC SD-125E RF LINK MODULE SD-125E V2 PARTS LIST SD-125E V2(148MHz~174MHz) DIGITAL BOARD(932-558193AB) PARTS LIST DC TO DC CONVERSION ASSY (501-902121AA) Reference No Description Code No Reference No Description Code No R801 1/16W 5% 1608 911-610057BG C810 0.01UF GRM39X7R103K25V 913-421004EK...
  • Page 60 MAXONCIC SD-125E RF LINK MODULE SD-125E V2(148MHz~174MHz) RF BOARD(932-558184AB) PARTS LIST 1/3 PWR MODULE V2 ASSY (501-902121AC) Reference No Description Code No Reference No Description Code No R(L707) 1/10W 2012 911-600007CA C703.706.710.712 0.01UF GRM40X7R103K50V 913-431004HK R703 1/10W 2012 911-610037CA C715 0.01UF...
  • Page 61 MAXONCIC SD-125E RF LINK MODULE SD-125E V2(148MHz~174MHz) RF BOARD(932-558184AB) PARTS LIST 2/3 RF CIRCUIT ASSY (501-382121AA) R126.C63.LK17 1/16W 1005 911-600007BF C34.40 0.001UF GRM40 X7R102K 50V 913-431003HH R14.53 1/16W 1005 911-610027BF C23.50.73.78.84.98 0.001UF GRM36X7R102K50V 913-411003HH R1.2.12.13.38.66 1/16W 5% T 1005 911-610037BF C114,121.122.131...
  • Page 62 MAXONCIC SD-125E RF LINK MODULE SD-125E V2(148MHz~174MHz) RF BOARD(932-558184AB) PARTS LIST 3/3 TX VCO V2 BAND ASSY (501-362121AB) R201 1/16W 1005 911-600007BF C214.216.217 0.001UF GRM36X7R102K50V 913-411003HH R202 1/16W 5% T 1005 911-610037BF C205 1.2PF GRM36COG1R2C50V 913-411200HB R203 100K 1/16W 5% T 1005...

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