
MAINTENANCE MANUAL FOR
21.4 MHz RECEIVER IF MODULE
12.5/25 kHz CHANNEL SPACING
19D902783G7 & G11
DESCRIPTION
The MASTR III Receiver IF Module provides amplifi-
cation and demodulation of the 21.4 MHz Intermediate
Frequency signal. The IF Module also includes the re-
ceiver squelch circuitry. However, it does not include de-
emphasis or squelch audio gating circuits. Figure 1 is a
block diagram showing the functional operation of the IF
Module.
The IF Module circuitry contains the following:
•
A 50 ohm input impedance IF Amplifier
•
A chain of two crystal filters and an integrated
circuit IF amplifier
•
An integrated circuit containing a crystal oscillator,
mixer, limiter, and quadrature detector
•
A variable gain AF amplifier
•
A squelch circuit
•
A fault detector circuit
•
An integrated circuit voltage regulator
•
An address decoder
TABLE OF CONTENTS
Page
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Front Cover
GENERAL SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
CIRCUIT ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
INPUT MATCHING NETWORK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
CRYSTAL FILTERS, IF AMPLIFIERS . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
OSCILLATOR/MIXER/DETECTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
AUDIO AMPLIFIER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
SQUELCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
Buffer Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
Bandpass Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
Noise Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
DC Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
Schmitt Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
FAULT DETECTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
VOLTAGE REGULATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
ADDRESS DECODER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
RECOMMENDED TEST EQUIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
ALIGNMENT PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
ASSEMBLY DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
OUTLINE DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5
IC DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10
PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11
PRODUCTION CHANGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Back Cover
LBI-39123E
ERICSSONZ
Ericsson Inc.
Private Radio Systems
Mountain View Road
Lynchburg, Virginia 24502
1-800-528-7711 (Outside USA, 804-592-7711)
Printed in U.S.A.
PRODUCTION CHANGES
Changes in the equipment to improve performance or to simplify
circuits are identified by a "Revision Letter" which is stamped after the
model number of the unit. The revision stamped on the unit includes all
previous revisions. Refer to the Parts List for the descriptions of parts
affected by these revisions.
REV. B - RECEIVER IF MODULE 19D902494G7
To improve production of Group 7 boards.
New schematic (193D1065).
REV. A - RECEIVER IF MODULE 19D902494G11
To ensure correct operation, U7 (19A701789P4) was replaced.
REV. B - RECEIVER IF MODULE 19D902494G11
To increase margins on squelch threshold sensitivity and 12 dB
SINAD in 12.5 kHz mode. C86 was 0.01
µ
F (19A702052P14),
R6 was 50 ohms (19B800607P510), R97 was 39 ohms
(19B801251P390) and R98 and R99 were 150 ohms
(19B801251P151). Added L6 (19A705430P24).
Содержание 19D902783G1
Страница 6: ...SCHEMATIC DIAGRAM RECEIVER IF MODULE 19D902494G1 19D902504 Sh 1 Rev 6 LBI 38643C 5...
Страница 7: ...SCHEMATIC DIAGRAM RECEIVER IF MODULE 19D902494G1 19D902504 Sh 2 Rev 6 LBI 38643C 6...
Страница 20: ...SCHEMATIC DIAGRAM UHF TRANSMITTER SYNTHESIZER 19D902780G3 G6 G10 19D903363 Sh 1 Rev 10 LBI 38671H 9...
Страница 21: ...SCHEMATIC DIAGRAM UHF TRANSMITTER SYNTHESIZER 19D902780G3 G6 G10 19D903363 Sh 2 Rev 10 LBI 38671H 10...
Страница 22: ...SCHEMATIC DIAGRAM UHF TRANSMITTER SYNTHESIZER 19D902780G3 G6 G10 19D903363 Sh 3 Rev 10 LBI 38671H 11...
Страница 33: ...ASSEMBLY DIAGRAM RECEIVER SYNTHESIZER MODULE 19D902781G3 G7 G8 G10 G12 19D902781 Sh 2 Rev 5 LBI 38672J 10...
Страница 34: ...SCHEMATIC DIAGRAM RECEIVER SYNTHESIZER MODULE 19D902664G3 G7 G8 G10 G12 19D904091 Sh 1 Rev 9A LBI 38672J 11...
Страница 35: ...SCHEMATIC DIAGRAM RECEIVER SYNTHESIZER MODULE 19D902664G3 G7 G8 G10 G12 19D904091 Sh 2 Rev 9A LBI 38672J 12...
Страница 36: ...SCHEMATIC DIAGRAM RECEIVER SYNTHESIZER MODULE 19D902664G3 G7 G8 G10 G12 19D904091 Sh 3 Rev 9A LBI 38672J 13...
Страница 42: ...RECEIVER FRONT END BOARD 19D902490G4 G7 OUTLINE DIAGRAM 19D902490 Sh 4 Rev 6A LBI 38673F 5...
Страница 43: ...ASSEMBLY DIAGRAM RECEIVER FRONT END MODULE 19D902782G3 19D902782 Sh 1 Rev 6 LBI 38673F 6...
Страница 44: ...ASSEMBLY DIAGRAM RECEIVER FRONT END MODULE 19D902782G4 G7 19D902782 Sh 2 Rev 6 LBI 38673F 7...
Страница 45: ...SCHEMATIC DIAGRAM RECEIVER FRONT END MODULE 19D902782G4 G7 19D904768 Sh 1 Rev 6 LBI 38673F 8...
Страница 46: ...SCHEMATIC DIAGRAM RECEIVER FRONT END MODULE 19D902782G3 G4 G7 19D904768 Sh 2 Rev 6 LBI 38673F 9...
Страница 47: ...SCHEMATIC DIAGRAM RECEIVER FRONT END MODULE 19D902782G3 19D903498 Rev 7 LBI 38673F 10...
Страница 48: ...This page intentionally left blank LBI 38673F 11...
Страница 54: ...ASSEMBLY DIAGRAM POWER AMPLIFIER ASSEMBLY 19D902797G3 G6 G7 G8 G9 G10 G11 19D902797 Sh 3 Rev 10 LBI 38674F 5...
Страница 56: ...ASSEMBLY DIAGRAMS LOW PASS FILTER MODULE 19D902856G3 19D902856 Sh 1 Rev 0 LBI 38674F 7...
Страница 60: ...SCHEMATIC DIAGRAM POWER AMPLIFIER ASSEMBLY 19D902797G3 G6 G7 G8 G9 G10 G11 19D903622 Sh 1 Rev 11 LBI 38674F 11...
Страница 71: ...ACCESSORIES ANTENNA SWITCH 19B235897P2 LBI 38675E 9...
Страница 78: ...SCHEMATIC DIAGRAM RECEIVER IF MODULE EARLIER VERSION 19D902494G7 G11 188D5586 Sh 1 Rev 3 LBI 39123E 5...
Страница 79: ...SCHEMATIC DIAGRAM RECEIVER IF MODULE EARLIER VERSION 19D902494G7 G11 188D5586 Sh 2 Rev 3 LBI 39123E 6...
Страница 80: ...SCHEMATIC DIAGRAM RECEIVER IF MODULE 19D902494G7 G11 193D1065 Sh 1 Rev 3 LBI 39123E 7...
Страница 81: ...SCHEMATIC DIAGRAM RECEIVER IF MODULE 19D902494G7 G11 193D1065 Sh 2 Rev 3 LBI 39123E 8...
Страница 82: ...SCHEMATIC DIAGRAM RECEIVER IF MODULE 19D902494G7 G11 193D1065 Sh 3 Rev 3 LBI 39123E 9...
Страница 90: ...ASSEMBLY DIAGRAM RECEIVER FRONT END MODULE 19D902782G6 G8 G12 19D902782 Sh 2 Rev 3 LBI 39129B 5...
Страница 91: ...SCHEMATIC DIAGRAM RECEIVER FRONT END MODULE 19D902782G6 G8 G12 188D5789 Sh 1 Rev 6A LBI 39129B 6...
Страница 92: ...SCHEMATIC DIAGRAM RECEIVER FRONT END MODULE 19D902782G6 G8 G12 188D5789 Sh 2 Rev 6A LBI 39129B 7...