Daniels Electronics MT-3 Series Instruction Manual Download Page 17

Page: 17 / 56

Theory of Operation

MT-3 FM Transmitter Mainboard Instruction Manual

IM20-MT3TXMN

fm audio Processor Block diagram

Splatter

Filter

Pre-

emphasis

Select

Pre-

emphasis

Select

Compression

Amp

Compression

Amp

Limiter/Summing

Amplifier

Buffer

+4 V

Regulator

+4 V

Pre-

emphasis

Select

Auxillary

Buffer

Amp

Tx Audio

Control

Audio

Switch 1

Audio

Switch 2

Regular Modulation

Buffer

Subtone

3 KHz

Direct Modulation

Offset Buffer

TCVCXO

Modulation Buffer

Offset

TCVCXO

DC Level

Adjust

Reg Mod

Out

Low Freq

Out

Inverting Amp

Coupling

Select

2 Port

Polarity

Select

JU35

JU34

Tx Audio

Control

3dB

Narrow

Band

Pad

JU14

JU26

JU27

JU30

JU43

JU28

JU25

49K9

P1-3

U1A

U1B

P1-1

R31

Tone

Digital

Input

P2-1

Balanced

Input

Microphone

Input

U3A

U3B

U2A

U2C

U2D

P2-2

R48

R42

Direct

Modulation

Input

P4-3

U2B

R87

P4-4

P4-2

P3-1

U3C

U3D

P4-1

JU4

Subtone

JU13

R36

JU12

JU11

B0232

FIGURE 1

Summary of Contents for MT-3 Series

Page 1: ...means electronic mechanical photocopying recording or otherwise without the prior written consent of Daniels Electronics Ltd The stylized Daniels Electronics Ltd and DE logo are registered Canadian a...

Page 2: ...identify the significance of a revision Each element of the revision number signifies the scope of change as described in the diagram below DOCUMENT REVISION DEFINITION Major Revisions The result of...

Page 3: ...ard Interconnection Pin Definitions 26 FM Audio Processor Alignment 27 Troubleshooting 31 Temperature Compensation 32 FM Audio Processor Jumper Configurations 32 Illustrations and Schematics 35 MT 3 F...

Page 4: ...iv MT 3 FM Transmitter Mainboard Instruction Manual IM20 MT3TXMN This Page Intentionally Left Blank...

Page 5: ...the amplifier and the synthesizer modules are frequency band sensitive plug in modules Circuitry and jumpers on the transmitter mainboard control the operation of the modules as well as the overall o...

Page 6: ...2 MT 3 FM Transmitter Mainboard Instruction Manual IM20 MT3TXMN This Page Intentionally Left Blank...

Page 7: ...Emissions Conducted Spurious 90 dBc 80 dBc VSWR Protection 20 1 VSWR at all phase angles Operating Temperature Range 30 C to 60 C Operating Humidity 95 RH non condensing at 25 C Operating Voltage 13...

Page 8: ...s standard MT 3 Repeater Subrack Subracks modules comply with IEEE 1101 DIN 41494 and IEC 297 3 mechanical size modular arrangement External Connections RF Connection Type N connector located on the m...

Page 9: ...en SW1 is in the OFF position the transmitter is turned off however 13 8 VDC is still present on the transmitter mainboard as the 13 8 VDC supply is not switched When SW1 is in the KEYED position 9 5...

Page 10: ...of U2a goes low which triggers the transmitter s TOT located on the FM Audio Processor The TOT s output is AND ed with the MIC PTT NTO signal U2c and the PTT NTO signal U2d When any one of the preced...

Page 11: ...for the synthesizer module PTT input Q4 Turns on Q5 which turns on the 9 5 VDC Switched supply Q6 Turns on Q7 which turns on the 9 5 VDC PTT Switched supply The 9 5 VDC Switched supply Q5 can also be...

Page 12: ...and balanced audio compression amplifiers will be disabled eliminating the use of the front panel microphone jack for local microphone operations With this configuration the balanced audio is routed a...

Page 13: ...B18 and Z18 by a transformer T1 Two audio outputs from the FM Audio Processor are routed to the synthesizer modules Microphone Audio Normally the microphone audio is sent from the attached transmitter...

Page 14: ...orward and reverse power sense lines to the backplane connector pins B26 and Z26 respectively The forward and reverse power sense lines from the amplifier can be open collector or linear outputs depen...

Page 15: ...t side of the transmitter mainboard J32 J31 J29 J28 J26 J27 Minutes I I I I I I 0 01 I I I I I N I 0 01 I I I I N I I 0 01 I I I N I I I 0 01 I I I N I I N I 0 02 I I N I I I I 0 02 I I I N I N I I 0...

Page 16: ...s in transmitter deviation over temperature caused by changing characteristics of synthesizers and oscillators A single chip 10th Order Linear Phase Low Pass Splatter Filter for increased cut off atte...

Page 17: ...ch 2 Regular Modulation Buffer Subtone 1 3 KHz Direct Modulation Offset Buffer TCVCXO Modulation Buffer Offset TCVCXO DC Level Adjust Reg Mod Out Low Freq Out Inverting Amp Coupling Select 2 Port Pola...

Page 18: ...z tone at 18 dBm gives 500 Hz All Other Audio Inputs Disabled Interconnection Pin Layout Diagram PCB 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 P1 P2 P4 P3 Balanced Input END VIEW Mic Input Subtone Inp ut 1 8V 9...

Page 19: ...low frequency modulation capabilities of the synthesizer module The DIRECT MODULATION inputs on the J1 control connector of the MT 3 Motherboard will be used B20 for TX A and A20 for TX B Turn on Tim...

Page 20: ...nse jumper JU1 at Y and X position respectively FM Audio Processor Balanced Input The 600 balanced input uses the ALC pre amplifier U1B with input level control pot R31 The balanced input level contro...

Page 21: ...ion Output port while Subtone 2 is used for DCS Both subtone inputs have an input level control In order to maintain a uniform frequency response from 50 Hz to 300 Hz dual port modulation techniques a...

Page 22: ...CROPHONE COMPRESSION CONTROL X Y X Y X Y FLAT AUDIO PRE EMPHASIS X Y TWO PORT POLARITY SUBTONE 1 INPUT CONTROL LEVEL 3 P1 2 P1 1 P1 4 P1 3 P3 3 P2 1 P2 4 P2 9 5V CONTINUOUS C10 10nF 4K53 R46 C5 10nF 1...

Page 23: ...el temperature compensation for synthesizer sensitivity variations Due to the many different characteristics of various synthesizers many components are selected for best performance over the temperat...

Page 24: ...D FOR DIGITAL MOD AUXILIARY INPUT LEVEL CONTROL X Y MICROPHONE AGC PREAMP BALANCED AGC PREAMP hi gh w i deband sel ect l ow nar r ow band sel ect X Y BALANCED COMPRESSION CONTROL FLAT AUDIO PRE EMPHAS...

Page 25: ...rrying half the audio level as determined by resistive divider comprised of R22 and R21 X Y DEVIATION CONTROL LOW FREQUENCY DIRECT MODULATION OUTPUT X Y X Y X Y 10 POLE LOWPASS FI LTER X Y X Y VOICE S...

Page 26: ...22 MT 3 FM Transmitter Mainboard Instruction Manual IM20 MT3TXMN This Page Intentionally Left Blank...

Page 27: ...sing an ordinary soldering iron Removal and replacement of surface mount components should be performed only with specifically designed surface mount rework and repair stations complete with Electrost...

Page 28: ...ppm frequency tolerance General Information Before proceeding with the transmitter alignment check that the appropriate jumpers are installed See Standard Factory Settings and Jumper Configuration sec...

Page 29: ...talled Amplifier power sense output configuration J13 X Amplifier power sense output configuration J14 X Amplifier power sense output configuration J15 X Amplifier power sense output configuration J16...

Page 30: ...o the MT 3 Motherboard Pin Name Pin Name Pin Name D2 No Connect B2 13 8 VDC Z2 13 8 VDC D4 No Connect B4 MIC Out Z4 MIC In D6 No Connect B6 9 5 VDC Z6 9 5 VDC D8 No Connect B8 Relay Positive Z8 Relay...

Page 31: ...tter is most commonly set up for a single frequency operation there are times when an application requires multiple frequencies per transmitter This also changes the standard tuning procedure slightly...

Page 32: ...AF Gen 1 kHz Tone 18 dBm 5 R42 Subtone1 Adjust and measure 500 Hz Deviation Monitor 6 OST 3H035 2 Port OST 3H045 2 Port Change AF Gen freq AF Gen 40 Hz 18 dBm 7 R36 TCXO Adjust and measure 500 Hz 8 Su...

Page 33: ...d measure Distortion Analyzer AF Filter 15 kHz 4 0 THD 19 Microphone Input Front Panel Pin 2 Change level AF Gen 1 kHz Tone 10 dBm 20 R2 Microphone Adjust and measure 3 kHz Deviation monitor 21 Microp...

Page 34: ...3H035 2 Port OST 3H045 2 Port Change AF Gen freq AF Gen 40 Hz 18 dB 7 R36 TCXO Adjust and measure 500 Hz 8 Subtone 1 input Change AF Gen freq AF Gen 300 Hz 18 dBm 9 Deviation Monitor Should measure 50...

Page 35: ...Test Subtone Measured 1 8 kHz 10 dBm 1 kHz 8 dBm 1 kHz 10 dBm 100 kHz 18 dBm TP3 5 2 V P P 3 8 V P P N A N A TP12 N A N A 3 8 V P P N A TP10 6 5 V P P 4 9 V P P 4 8 V P P 1 1 V P P TP5 2 4 V P P 1 3 V...

Page 36: ...a constant transmitter audio deviation with a fixed level input signal It is capable of not only compensating for temperature related level variations within the audio processor typically 0 3 to 0 5 d...

Page 37: ...XY X Audio Gate Switch X X X 22 XY Y Splatter Filter Enable Bypass Y Y Y 23 Single Open Narrow Band Gain Reduction Open Open Open 24 XY Factory Custom Temperature Compensation Network Contact Factory...

Page 38: ...MT 3 FM Transmitter Mainboard Instruction Manual IM20 MT3TXMN 34 This Page Intentionally Left Blank...

Page 39: ...ring convention in which the last two digits of the circuit board number represent the circuit board version All PCBs manufactured by Daniels Electronics Ltd are identified by one of the following num...

Page 40: ...ED J12 R25 27K4 R26 1K0 Q10 PZT2222A J14 J15 J13 FUSE OPTIONAL 9 5 VDC CONTINUOUS J9 SQL DE EMP INPUT MIC OUT MIC IN BALANCED INPUT SIDE 2 600 OHMS BALANCED INPUT SIDE 1 SUBTONE INPUT 1 SUBTONE INPUT...

Page 41: ...LPF22 B B4 LPF23 B B3 LPF24 B B3 LPF25 B B3 LPF26 B B3 LPF27 B B3 LPF28 B B2 LPF29 B B2 LPF30 B B2 LPF31 B B2 LPF32 B B2 LPF33 B B1 LPF34 B B1 LPF35 B B1 Q1 B E6 Q3 B E5 Q4 B F5 Q5 B F4 Q6 B E5 Q7 B E...

Page 42: ...PF3 B B7 LPF4 B B7 LPF5 B B7 LPF8 B B6 LPF10 B B6 LPF12 B B6 LPF15 B B5 LPF18 B B4 LPF19 B B4 LPF20 B B4 LPF21 B B4 LPF22 B B4 LPF23 B B3 LPF24 B B3 LPF25 B B3 LPF26 B B3 LPF27 B B3 LPF28 B B2 LPF29 B...

Page 43: ...1 3 X Y Y X Y X Y X Y UNDER U6 X Y X Y X Y JA5 1 JA5 2 JA5 3 JA5 4 JA2 4 JA3 1 JA4 2 JA3 2 JA4 4 JA1 4 JA3 3 JF2 3 JF2 4 JF1 4 JA3 4 JA2 3 JA4 3 JA4 1 JA2 1 JA2 2 JA1 1 JA1 2 JA1 3 JF1 1 JF1 3 JF2 2 J...

Page 44: ...E REVISED BY REV DANIELS ELECTRONICS LTD TM VICTORIA BC SW1 PF3 MIC J2 D1 C1 HIGHEST REFERENCE DESIGNATORS UNUSED REFERENCE DESIGNATORS 03 JUL 03 SHANE AEBISCHER 1 2 43 921212 M GAUBE 07 APRIL 92 MT 3...

Page 45: ...4 1 2 3 C38 3 3nF P2 P3 P4 C37 3 3nF C32 N I P1 P5 P8 P6 P7 C15 3 3nF R19 THD N I C34 1 0 uF R27 THD N I R1 J1 R2 K3 R3 H1 R4 J1 R5 I2 R6 J2 R7 H2 R8 E2 R9 E2 R10 H2 R11 G2 R12 A1 R13 F1 R14 O3 R15 F...

Page 46: ...TER Y X Y X Y X 10 POLE LOWPASS FILTER Y X Y X OPTIONAL Y X BALANCED AGC PREAMP MICROPHONE AGC PREAMP Y X AUXILIARY INPUT LEVEL CONTROL NOT INSTALLED FOR DIGITAL MOD 9 5V CONTINUOUS Y X Y X Y X Y X LO...

Page 47: ...5A104K5R C10 CAP 1uF CER 2225 5 50V X7R 1008 6H105J5R C12 CAP 10nF CER 0805 10 50V X7R 1008 4A103K5R C13 CAP 10nF CER 0805 10 50V X7R 1008 4A103K5R C14 CAP 10nF CER 0805 10 50V X7R 1008 4A103K5R C15 C...

Page 48: ...T PF2 HEADER 1 R A 2 ROW X 2PIN 5010 H202RA9T PF3 HEADER 1 R A 2 ROW X 2PIN 5010 H202RA9T Q1 TRANSISTOR BC817 25 NPN SOT23 2120 BC817025 Q3 TRANSISTOR BC817 25 NPN SOT23 2120 BC817025 Q4 TRANSISTOR BC...

Page 49: ...K1 0805 1 100ppm 1150 4A6812FP R34 RES SM 27K4 0805 1 100ppm 1150 4A2742FP R35 RES SM 27K4 0805 1 100ppm 1150 4A2742FP R36 RES SM 221K 0805 1 100ppm 1150 5A2213FP R37 RES SM 1K00 0805 1 100ppm 1150 3A...

Page 50: ...EXAN 14HP VHF ORANGE 3536 10101405 1 LBL LOCKWASHER M3 SPLIT A2 STEEL 5814 3M0LK00S 4 EA NAMEPLATE BLANK 14HP ALUM 3702 10001214 1 EA NUT M2 5 HEX 5 0mm FLATS A2 for CONN1 5813 2M5HX50S 2 EA NUT M2 5...

Page 51: ...uF C 1206 80 20 25V X7R 1008 6B105Z3R C5 CAP 10nF CER 0805 10 50V X7R 1008 4A103K5R C6 CAP SM 1uF TANT 20 16V 1055 5A105M16 C7 CAP 680nF CER 1206 20 25V X7R 1008 5B684M3R C8 CAP SM 4 7uF TANT 10 16V 1...

Page 52: ...0 25V X7R 1008 6B105Z3R C47 CAP 1uF C 1206 80 20 25V X7R 1008 6B105Z3R C48 CAP SM 4 7uF TANT 10 16V 1055 5B475K16 C49 CAP 10nF CER 0805 10 50V X7R 1008 4A103K5R C50 CAP SM 4 7uF TANT 10 16V 1055 5B475...

Page 53: ...ppm 1150 4A4992FP R35 RES SM 1K00 0805 1 100ppm 1150 3A1001FP R36 POT SM 4mmSQ 50K MUL TRN SIDE 1174 DM3503J0 R37 RES SM 49K9 0805 1 100ppm 1150 4A4992FP R38 POT SM 4mmSQ 5K0 MUL TRN SIDE 1174 DM2502J...

Page 54: ...ES SM 16K2 0805 1 100ppm 1150 4A1622FP R77 RES SM 20K0 0805 1 100ppm 1150 4A2002FP R78 RES SM 10K0 0805 1 100ppm 1150 4A1002FP R79 RES SM 49K9 0805 1 100ppm 1150 4A4992FP R80 RES SM 27K4 0805 1 100ppm...

Page 55: ...sion 1 8 2 2 2 3 Audio Processors Issue 4 contains no AM information the document title is changed to reflect coverage of only FM transmitters 699 For VT 3H035 VT 3H045 transmitters to reduce spurious...

Page 56: ...eferences 6113 VT 3 140 Audio Processor select value table updated 6115 VT 3 160 Audio Processor select value table updated 4 5 0 Feb 06 6129 UT 3 420 SXCX00 Audio Processor select value table updated...

Search results

Summary of Contents for MT-3 Series

Reviews:

Related manuals for MT-3 Series

Brands by name

Popular brands

Daniels Electronics MT-3 Series, Instruction Manual

Search results

Summary of Contents for MT-3 Series

Reviews:

Related manuals for MT-3 Series

Brands by name

Popular brands