Midland 70-1341 Service Manual Download Page 33

Page: 33 / 68

SERVICING

70-1341/1344/1441/1444

4 - 9

Troubleshooting Chart 3 – 3 — Transmitter Problem

YES

START

No transmit

audio?

No output

power, or low

output power?

Transmitter

off-frequency?

DONE

Suspect D501,

D502, D503,

D504 and D505

Suspect Q710

Go to Logic

Troubleshooting

Chart, page 4 - 12

Go to Modulator
Troubleshooting

Chart, page 4 - 14

YES

D501,

D502, D503,

D504 and D502

biased in TX

mode?

YES

Transmit

Audio

Distorted?

YES

Q501,

Q503, Q504

and Q708

OK?

Suspect Q501,
Q503, Q504 or

Q708

YES

D507,
IC501

and Q509

OK?

Suspect D507,

IC501 or Q509

Summary of Contents for 70-1341

Page 1: ...SERVICE MANUAL 70 1341 70 1344 70 1441 70 1444 FM TWO WAY LAND MOBILE RADIO TITAN VHF HIGH BAND 150 174 MHz 12 5 30 WATT 70 134100 4 99...

Page 2: ...t service or improvement Printed on BLUE paper Change Notice CN For details about changed made during production by model and serial number Printed on YELLOW paper Manual Correction MC For correcting...

Page 3: ...MS Block Diagram 6 3 Wiring Diagram 6 4 TR 1529 Layout Bottom View 6 5 TR 1529 Layout Top View 6 6 RF Schematic Diagram 6 7 Logic Schematic Diagram 6 8 Z 1022 Schematic Diagram 6 9 Z 1023 Schematic Di...

Page 4: ...iv...

Page 5: ...SECTION 1 GENERAL INFORMATION SECTION 2 PREPARATION SECTION 3 INSTALLATION SECTION 4 SERVICING SECTION 5 CIRCUIT DESCRIPTIONS SECTION 6 DIAGRAMS SECTION 7 PARTS v...

Page 6: ...on CTCSS Continuous Tone Controlled Squelch System DCS or CDCSS Continuous Digital Controlled Squelch System DTMF Dual Tone Multi Frequency EEPROM Electrically Erasable Programmable Read Only Memory M...

Page 7: ...SECTION 1 GENERAL INFORMATION...

Page 8: ...GENERAL INFORMATION 70 1341 1344 1441 1444 NOTES 1 2...

Page 9: ...nk Mount Standard Control Head with Internal Speaker 70 1444 VHF Titan Mobile Trunk Mount Deluxe Control Head with 70 2357 External Speaker SPECIFICATIONS Refer to TIA EIA 603 standards for measuremen...

Page 10: ...z 75 dB SQUELCH SENSITIVITY 0 18 V maximum AUDIO POWER OUTPUT Internal Speaker 3 W less than 3 Distortion External Speaker 10 W less than 3 Distortion TRANSMITTER RF OUTPUT 50 W FREQUENCY STABILITY 0...

Page 11: ...erface Cable 70 1470 PC Programming Software 70 1473 Programming Kit 70 2183 320 Channel Plug In Module 70 2184 DTMF Programming Microphone 70 2202 Standard Control Head 70 2203 Deluxe Control Head 70...

Page 12: ...GENERAL INFORMATION 70 1341 1344 1441 1444 1 6 NOTES...

Page 13: ...SECTION 2 PREPARATION...

Page 14: ...PREPARATION 70 1341 1344 1441 1444 NOTES 2 2...

Page 15: ...174 MHz peak responding 5 kHz range Modulation level measurements Frequency Meter or Frequency Counter 136 174 MHz 1 0 ppm accuracy Carrier frequency measurement RF Signal Generator 136 174 MHz range...

Page 16: ...e Oscillator 4 Click on the Transmit button any channel Measure transmitted RF carrier frequency without modulation Adjust trimmer cap X701 for a carrier frequency within 300 Hz of channel frequency P...

Page 17: ...iation DTMF Squelch 11 Clear the CTCSS tone then initiate transmit using the programmer 6 Press the Channel Mode knob until SQL appears in the display Rotate the Channel Mode Knob until 80 appears in...

Page 18: ...PREPARATION 70 1341 1344 1441 1444 2 6 Figure 2 Adjustment Map L215 L216 L217 L702 L713 X701 RV401 RV402 TX TANK RX TANK REFERENCE OSCILLATOR DCS MODULATION SQUELCH FIRST IF...

Page 19: ...SECTION 3 INSTALLATION...

Page 20: ...INSTALLATION 70 1341 1344 1441 1444 NOTES 3 2...

Page 21: ...nt handle Tighten screws to TX RX unit 7 Locate two hole caps No 50 Press hole caps into holes Tighten bottom lid 8 Locate control head back No 41 Take lock nut off other end of control cable Slide ca...

Page 22: ...sceiver is designed to operate from a 12 V DC negative ground automotive electrical system Current drain of at least 10 A should be expected Inspection of the vehicle is recommended prior to installat...

Page 23: ...444 3 5 6 7 8 9 10 1 2 3 4 5 Red Wires 15 Amp Fuse Brown Jumper Wire used with Internal Speaker Only 70 2357 External Speaker Required for 70 1344 1444 Black Wires Red Battery Post Vehicle Ground Figu...

Page 24: ...INSTALLATION 70 1341 1344 1441 1444 NOTES 3 6...

Page 25: ...SECTION 4 SERVICING...

Page 26: ...SERVICING 70 1341 1344 1441 1444 NOTES 4 2...

Page 27: ...ays Just touch bench ground when you sit down so that you and the grounded work area are at the same potential REPLACING CHIP CAPACITORS AND RESISTORS This section describes the best way to remove a c...

Page 28: ...ers or longnose pliers Discard the component CAUTION Application of too much solder can create solder bridges between PC patterns under the soldered component and around the pad 4 4 Figure 4 1 2 Compl...

Page 29: ...short the pads together Let the hot solder flow onto the component do not touch the component with the iron Repeat to finish the other end of the component Solder must adhere to all metallic end surf...

Page 30: ...loose from the inside of the cleaned out hole Cutting the defective components away from its leads first makes removing the leads and solder easier Before installing a new component remove all solder...

Page 31: ...y blank or incorrect DONE Check EEPROM Module IC902 If problem persists see Logic Troubleshooting Chart page 4 12 Replace faulty fuse Suspect IC901 Suspect IC301 IC301 OK Fuse F201 and Mainline Fuse O...

Page 32: ...O NO Q717 IC704 and IC705 OK Error Code 8 or 9 Displayed Error Code 2 or 4 Displayed No Backup Data Check backup power supply Unplug and check programmer or cloning cables Check path from IC701 pin 7...

Page 33: ...equency DONE Suspect D501 D502 D503 D504 and D505 Suspect Q710 Go to Logic Troubleshooting Chart page 4 12 Go to Modulator Troubleshooting Chart page 4 14 NO YES YES NO D501 D502 D503 D504 and D502 bi...

Page 34: ...D505 Suspect IC404 Check for audio present at IC203 pin 1 Poor sensitivity Go to 1 Audio present at IC404 pins 1 7 8 and 14 Suspect C549 C550 or L518 Suspect D202 L209 or L210 Suspect IC901 Antenna O...

Page 35: ...L217 NO NO NO YES YES Signal distorted 44 545 MHz at X201 1 NO RV402 OK IC402 pin 6 goes Low to High adjusting squelch Suspect IC402 Suspect Q203 Suspect Q204 Suspect X201 Check IC401 and IC404 NO YES...

Page 36: ...smitter off frequency No transmit receive or channel display Go to Control Head Troubleshooting Chart page 4 13 Transmitter still off frequency Suspect X701 X901 OK NO YES Suspect X901 DONE 5 V at IC9...

Page 37: ...NO NO YES YES Display blank or incorrect Suspect IC304 Are all lights on NO DONE Suspect IC301 YES NO Suspect IC305 5 V at IC303 pin 1 START Suspect PT301 Q302 or Q303 NO Display responds when a key i...

Page 38: ...1 Suspect microphone Suspect X701 YES Suspect IC402 NO Suspect IC702 IC702 OK YES Signal at source of Q706 and IC703 pin 2 VCO signal present at collector of IC705 NO YES Audio at IC401 pins 4 and 6 D...

Page 39: ...SECTION 5 CIRCUIT DESCRIPTION...

Page 40: ...CIRCUIT DESCRIPTION 70 1341 1344 1441 1444 NOTES 5 2...

Page 41: ...z sample of VCO output Normally the loop response is slowed enough by the active filter to block 5 0 kHz reference noise and prevent loop correction of voice modulation during transmit Higher active f...

Page 42: ...output is an open collector that sinks voltage to logic low when on channel receiver input is above the squelch threshold established by RV402 Level detector output is supplied through NSQ the interc...

Page 43: ...701 CTCSS DCS circuitry display circuitry and any signaling options DC Power and Reset 5V DC power to all logic circuitry in the logic section is supplied from switched 13 6V and is regulated by IC905...

Page 44: ...P53 I NSQ Noise Squelch Status High Receive 17 INT3 RDF 18 INT2 TCLK 19 TOUT O BEEP Beep Tone Output 20 P47 I O RTS Programmer Interface 21 P46 I O CTS Programmer Interface 22 TXD1 I O RD Programmer I...

Page 45: ...03 TXDL2 54 P02 TX LPSW 55 P01 TX PLCL 56 P00 TX STB 57 P37 DIR 58 P36 MOD LSB 59 P35 W N 60 61 P33 I DEPOW IN 62 P32 I TA SW IN 63 P31 O AUX SW OUT 64 P30 I O AUX STB Serial Data Strobe for AUX 65 P8...

Page 46: ...CIRCUIT DESCRIPTION 70 1341 1344 1441 1444 5 8 NOTES...

Page 47: ......

Page 48: ......

Page 49: ......

Page 50: ......

Page 51: ......

Page 52: ......

Page 53: ......

Page 54: ......

Page 55: ......

Page 56: ......

Page 57: ......

Page 58: ......

Page 59: ...SECTION 7 PARTS...

Page 60: ...PARTS 70 1341 1344 1441 1444 7 2 NOTES...

Page 61: ...ER 1 70 157841 39 CLIP 1 70 089465 C251 B CERAMIC 25 V 10000 pF 10 70 138625 41 TM BACK COVER 70 013053 C253 T CERAMIC 50 V 12 pF 5 70 138655 42 TM RUBBER RING 70 157821 C254 T CERAMIC 50 V 27 pF 5 70...

Page 62: ...04 T 2SK360E 70 080413 Q205 B RT1B241C 70 080521 Q206 B RT1B241C 70 080521 REF NO LOC DESCRIPTION PART NO INTEGRATED CIRCUITS IC202 T TA31136FN 70 076853 IC203 T TDA1519A 70 076854 IC204 T HA178L05UA...

Page 63: ...ECTOR 285D 9880J101 70 159858 LCD301 T LCD LCD9819JH 70 202094 P301 T CONNECTOR DF11 22DP 2DS 70 159857 P303 T CONNECTOR S2B PH 70 159337 PT301 T DIODE P1201 70 085084 RC301 T CONNECTOR ZCC 518 70 157...

Page 64: ...ETAL 1 32 W 39 kOHM 5 70 144356 R469 T METAL 1 32W 10 kOHM 5 70 144344 R470 T METAL 1 4 W 270 OHM 5 70 144193 R472 B METAL 1 10 W 1 kOHM 5 70 144353 R473 B METAL 1 10 W 180 kOHM 5 70 144309 R474 B MET...

Page 65: ...330 OHM 5 70 144164 R517 B METAL 1 10 W 5 6 kOHM 5 70 144168 R518 B METAL 1 10 W 47 kOHM 5 70 144231 R530 B METAL 1 32 W 0 OHM 5 70 144562 R532 B METAL 1 10 W 1 kOHM 5 70 144353 R533 B METAL 1 10 W 1...

Page 66: ...AL 1 10 W 47 kOHM 5 70 144342 R718 B METAL 1 32 W 2 7 kOHM 5 70 144674 R719 T METAL 1 10 W 22 OHM 5 70 144657 R721 T METAL 1 10 W 47 OHM 5 70 144348 R722 T METAL 1 10 W 47 kOHM 5 70 144342 R723 T META...

Page 67: ...C 25 V 0 1 uF 10 70 138598 C956 T CERAMIC 25 V 0 1 uF 10 70 138598 C957 T CERAMIC 25 V 0 1 uF 10 70 138598 C958 B CERAMIC 25 V 0 1 uF 10 70 138598 C959 B CERAMIC 25 V 10000 pF 10 70 138625 C960 B CERA...

Page 68: ...3628 MHz 70 128152 J901 T CONNECTOR DF11 24DP 2DSA 70 153126 D901 T HZM9B TR 70 085513 J903 T CONNECTOR IL Y 5P S15T2 EF 70 153127 D902 T DCB010 70 085245 D904 T IS2075 70 085001 TRANSISTORS Q901 T 2...

Search results

Summary of Contents for 70-1341

Reviews:

Related manuals for 70-1341

Brands by name

Popular brands

Midland 70-1341, Service Manual

Search results

Summary of Contents for 70-1341

Reviews:

Related manuals for 70-1341

Brands by name

Popular brands