Ericsson 19D902783G1 User manual

TABLE OF CONTENTS
Page
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Front Cover
GENERAL SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
CIRCUIT ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
INPUT MATCHING NETWORK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
CRYSTAL FILTERS, IF AMPLIFIERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
OSCILLATOR/MIXER/DETECTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
AUDIO AMPLIFIER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
SQUELCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
BufferAmplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
High Pass Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Noise Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
DCAmplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Schmitt Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
FAULT DETECTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
VOLTAGE REGULATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
RECOMMENDED TEST EQUIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
ALIGNMENT PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
ASSEMBLY DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
OUTLINE DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
PRODUCTION CHANGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
IC DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
MAINTENANCE MANUAL FOR
25kHz RECEIVER IF MODULE
19D902783G1
DESCRIPTION
The MASTR III Receiver IF Module provides ampli-
fication 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 matching network and
IF Amplifier
•A chain of two crystal filters and two integrated
circuit IF amplifiers
•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
LBI-38643C
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.

CIRCUITANALYSIS
INPUT MATCHING NETWORK
The input impedance matching network provides a 50 ohm
load for the receiver RF module. The network consists of C1
thru C3, L1 thru L3, and R1.
Capacitor C1 provides AC coupling and a DC block on the
input line (J1). This DC block protects the module in the event
of a failure in a preceding module. L2 and L3 are series reso-
nant at 21.4 MHz and provide a signal path to the FET ampli-
fier Q6. Parallel resonant circuit, L1 and C2, provide a path to
the 50 ohm load, R1, for frequencies other than 21.4 MHz.
CRYSTAL FILTERS, IF AMPLIFIERS
Y1, Y2, U1, U2, and associated circuitry provide IF filter-
ing and amplification at 21.4 MHz. Filters Y1 and Y2 are both
4 pole bandpass filters with a center frequency of 21.4 MHz
and a bandwidth of ±6.5 kHz. Amplifiers U1 and U2 are inte-
grated circuit amplifiers. U1 provides 30 dB of gain, U2 pro-
vides 18 dB of gain. The amplifiers and filters have terminal
impedances of 50 ohms. In circuit gain measurements can be
made using a high impedance probe.
Inductors L3, L4 and associated resistors and capacitors
provide power supply decoupling. R3 and R7 provide paths to
the input of the Fault Detector circuit. These inputs enable the
Fault Detector circuit to monitor the DC voltages of U1 and
U2.
The RF level detectors consist of transistors Q1 and Q2
along with associated resistors and capacitors. These detectors
play no role in the normal operation of the IF Module, but they
aid in unit testing and module troubleshooting.
OSCILLATOR/MIXER/DETECTOR
Integrated circuit U3 provides several functions including
2nd mixer, if amplifier and limiter, and quadrature detector.
The 20.945 MHz crystal oscillator provides local oscillator
injection to the mixer in U3. This mixer converts the 21.4 MHz
IF signal to 455 kHz. C20 and C21 are oscillator feedback ca-
pacitors and have been chosen to provide the proper capaci-
tance for crystal Y3. The proper oscillator output level is
difficult to measure directly without affecting the oscillation.
A preferable measurement is at TP3 which should read
about 50 mV pk. (Measured using a 10 megohm, 11 pF oscil-
loscope probe.)
The mixer is internally connected to the crystal oscillator.
Pins 16 and 3 of U3 are the mixer input and output respec-
tively. Typical mixer conversion gain is about 20 dB. The out-
put of the mixer drives the 4 pole ceramic bandpass filter FL1.
The limiter input is U3 pin 5, but the limiter output is inter-
nally connected to the detector and is not externally available.
A received signal strength indicator (RSSI) is provided at
U3 Pin 13. This indicator signal is generated within the limiter
circuitry and provides an output current proportional to the
logarithm of the input signal strength. This current develops a
voltage across R18. The voltage varies from about 0.7 Vdc for
noise input, to about 1 Vdc for a 12 dB SINAD signal, to a
maximum of about 2.7 Vdc for a high signal level (50 dB
stronger than that required for 12 dB SINAD).
The quadrature detector provides a demodulated audio fre-
quency output. The input to the detector is internally connected
to the limiter and is not externally available. The output of the
detector is U3 pin 9. R19 and C28 provide low-pass filtering to
remove 455 kHz feedthrough. Ceramic resonator Y4 provides
the frequency selective component needed for FM demodula-
tion. Y4 replaces the typical LC resonant circuit found in most
quadrature detectors. In contrast to the typical LC network, Y4
requires no adjustment.
The DC supply to U3 is provided through voltage dropping
resistor R11 to U3 pin 4. R12 provides a path to the input of
the Fault Detection circuit. This enables the Fault Detector to
monitor the DC voltage on U3.
AUDIO AMPLIFIER
Operational amplifier U6.3 provides audio frequency am-
plification. Its gain is set by its associated resistors, including
variable resistor VR1. VR1 allows for adjusting the AF output
level to 1 Vrms with a standard input signal to the module (1
kHz AF, 3 kHz peak deviation). U6.2 is used as a voltage regu-
lator to provide 4 Vdc for biasing the Operational amplifier.
SQUELCH
BufferAmplifier
Integrated circuit U6.4 is configured as a unity gain buffer
amplifier. It provides a high input impedance to minimize load-
ing of the previous circuits.
Copyright© February 1992, Ericsson Inc.
TABLE 1 - GENERAL SPECIFICATIONS
ITEM SPECIFICATION
I.F. frequency 21.4 MHz
Input Impedance 50 ohm
12 dB SINAD -120.0 dBm
Adj. CH SEL (25 kHz) -103 dB
Image (20.49 MHz) -100 dB
3rd order Intercept Pt 23 dBm
Variation of Sensitivity with Signal Frequency 2 kHz
2nd I.F. frequency 455 kHz
2nd L.O. frequency 20.945 MHz
AF output (J2 pin 31C) 1 Vrms adjustable (with standard input signal)
AF output impedance 1k ohm
AF distortion 5%
AF response
10 Hz -3 dB
300 Hz ±1 dB
1000 Hz 0 dB reference
3 kHz ±1 dB
Hum & Noise -55 dB
RSSI output (J2 pin 20C) 0.7 to 2.7 Vdc prop to log (sig level)
RSSI time constant 5 ms
SQ Threshold Sensitivity -119 dBm
SQ Maximum Sensitivity -102 dBm
SQ Clipping 3 kHz
SQ Attack 150 ms
SQ Close 250 ms
SQ output (J2 pin 26C) 5V logic (low = squelched)
Fault output (J2 pin 11C) 5V logic (low = fault)
DC Supply 1 Vrms (adjustable)
LBI-38643C
1

Highpass Filter
The audio frequency highpass filter consists of U7.1 and its
associated circuitry. The purpose of this filter is to reject all
voice frequencies and allow only demodulated noise to pass.
The functioning of the squelch circuit depends upon the pres-
ence or absence of this noise. (When a signal is being received,
i.e. the receiver is quiet, the squelch circuit senses the absence
of noise and unsquelches the radio.)
Noise Detector
U7.2 along with associated components act as a noise de-
tector. The rectified output of U7.2 charges C44 to a nearly
constant DC voltage.
DC Amplifier
U7.3 is configured as a basic amplifier with a gain of 11.
Schmitt Trigger
U7.4 is configured as an amplifier with positive feedback.
This arrangement provides hysteresis in the output verses input
characteristic. This eliminates the possibility of the squelch cir-
cuit repeatedly cutting in and out when the input signal is near
a threshold. R56 and R57 act as a voltage divider to provide a 5
volt logic level output. (Logic High = unsqelched)
FAULT DETECTOR
U4 and U5 are voltage comparators. These are configured
into four "window detectors" which sense the presence of volt-
ages within specified ranges (windows).
The four window detector circuits are U4.1 & U4.2, U4.4
& U4.3, U5.1 & U5.2, and U5.4 & U5.3. These monitor DC
operating voltages on U6.2, U1, U2, and U3 respectively. R29
and R30 comprise a voltage divider to provide a 5 volt logic
level output. A fault is indicated when the output drops to zero.
Diode D1 and transistor Q3 monitor the output of the 8V
regulator. D1 is a 8.2 volt breakdown diode. If the regulator
output voltage should rise above 8.9 V (8.2 + 0.7 base-emitter
drop) Q1 will turn on and a fault will be indicated.
Transistors Q4 and Q5 are drivers for the front panel LED
CR1. These are powered from the +13.8 Vdc line before the
8V regulator. Therefore, if the regulator opens, a fault will still
be indicated.
VOLTAGE REGULATOR
U8 is a monolithic integrated circuit voltage regulator pro-
viding 8 Vdc. This powers all circuitry in the module with ex-
ception of the front panel LED and its drivers.
MAINTENANCE
RECOMMENDED TEST EQUIPMENT
The following test equipment is required to test the IF
Module.
1. FM Signal Generator; HP 8640B, HP 8657A, or
equivalent
2. AF Generator or Function Generator
3. Audio Analyzer; HP 8903B, HP 339A, or equivalent
4. Oscilloscope
5. DC Meter for troubleshooting
6. Power Supply; 13.8 Vdc @ 150 mA
ALIGNMENT PROCEDURE
1. Apply 13.8 Vdc supply to module.
2. Verify DC current consumption is between 90 and 150
mA.
3. Verify fault output is 0 to 0.5 Vdc and front panel LED
is off.
4. Apply a standard input signal to the module input. (-60
dBm, 21.4 MHz signal modulated with 1kHz AF, 3 kHz
peak deviation)
5. Set VR1 for 1 Vrms ±3% at module output (pin 31C on
96 pin connector J2).
Figure 1 - 25 kHz Receiver IF Module
LBI-38643C
2

TROUBLESHOOTING
Each IF amplifier has a nominal 18 dB gain. U2 has a
nominal gain of 30 dB. The mixer has about 20 dB gain with
proper LO injection. The proper crystal oscillator level is 50
mV pk measured at TP3.
The following four test points are provided on the PWB for
additional test capability:
TP1: 100 mV pk @ 21.4 MHz with -30 dBm input sig-
nal
TP2: 100 mV PK @ 21.4 MHz with -50 dBm input
signal
TP3: 50 mV pk @ 20.945 MHz independent of input
signal
TP4: 100 mV pk @ 455 kHz with -60 dBm input sig-
nal
All RF voltages measured with 10 Megohm, 11 pF probe.
ASSEMBLY DIAGRAM
TROUBLE SHOOTING GUIDE
SYMPTOM CHECK
(CORRECT READING SHOWN) INCORRECT READING INDICATES DEFECTIVE
COMPONENT
Fault indicator on Check DC voltages
+8V at U8 Pin 1
+4v at U Pin 7
5.5V at U1 output pin
3.3V at 2 output pin
4.4V at U3 Pin 4
If DC voltages not correct
U8 or associated components
U6 or associated components
U1 or associated components
U2 or associated components
U3 or associated components
If DC voltages correct
U4, U5, U6, D1, Q3, Q4, Q5
No audio - no
noise With no signal applied to module IF input Check for AF noise @ C29 ; 200mV
Check for AF noise @ U6 Pin 8: 1 V U3 or associated components U6 or associated components
Noise only - no
demodulated audio Check crystal oscillator: TP3 50 mVpk 20.945 MHz
Apply -30 dBm 21.4 MHz input, check TP1 100 mVpk
Apply -50 dBm 21.4 MHz input, check TP2 100 mVpk
Apply -60 dBm 21.4 MHz input, check TP4 100 mVpk
U3, Y3 or associated components
Q6, Y1, U1 or associated components
U2, Y2 or associated components
U3, FL1 or associated components
Poor 12 dB SINAD Check crystal oscillator: TP3 50 mVpk 20.945 MHz U3, Y3 or associated components
Apply -30 dBm 21.4 MHz input, check TP1 100 mVpk
Apply -50 dBm 21.4 MHz input, check TP2 100 mVpk
Apply -60 dBm 21.4 MHz input, check TP4 100 mVpk
Q6, Y1, U1 or associated components
U2, Y2 or associated components
U3, FL1 or associated components
No squelch
function With squelch pot maximum, or with module AUDIO/ SQUELCH/HI connected to SQUELCH/ARM input
and with no signal to module IF input:
Check Presence of 1 Vpk noise at U6 Pin 14 U6 or associated components
Check presence of 1 Vpk noise U7 at Pin 1
Check presence of 1 Vpk noise U7 Pin 1
Check DC voltage U7 at Pin 8: 7 V
Check DC voltage U7 Pin 14: 0.5 V U7 or associated components
RECEIVER IF MODULE
19D902783G1
(19D902783, Sh. 1, Rev. 3)
LBI-38643C
3

RECEIVER IF MODULE
19D902494G1
OUTLINE DIAGRAM
(19D902494, Sh. 1, Rev. 5B)
(19D902493, Comp. Side, Rev. 5)
LBI-38643C
4

SCHEMATIC DIAGRAM
RECEIVER IF MODULE
19D902494G1
(19D902504, Sh. 1, Rev. 6)
LBI-38643C
5

SCHEMATIC DIAGRAM
RECEIVER IF MODULE
19D902494G1
(19D902504, Sh. 2, Rev. 6)
LBI-38643C
6

PARTS LIST
SYMBOL PART NO. DESCRIPTION
R39 19B800607P104 Metal film: 100K ohms ±5%, 1/8 w.
R40 19B800607P332 Metal film: 3.3K ohms ±5%, 1/8 w.
R41 19A702931P285 Metal film: 7500 ohms ±1%, 200 VDCW, 1/8
w.
R42 19B800607P104 Metal film: 100K ohms ±5%, 1/8 w.
R43 19B800607P102 Metal film: 1K ohms ±5%, 1/8 w.
R44 19B800607P153 Metal film: 15K ohms ±5%, 1/8 w.
R45 19A702931P273 Metal film: 5620 ohms ±1%, 200 VDCW, 1/8
w.
R46 19B800607P104 Metal film: 100K ohms ±5%, 1/8 w.
R47 19B800607P563 Metal film: 68K ohms ±5%, 1/8 w.
R48 19B800607P822 Metal film: 8.2K ohms ±5%, 1/8 w.
R49 19B800607P103 Metal film: 10K ohms ±5%, 1/8 w.
R50 19B800607P104 Metal film: 100K ohms ±5%, 1/8 w.
R51 19B800607P334 Metal film: 330K ohms ±5%, 1/8 w.
R52 19B800607P103 Metal film: 10K ohms ±5%, 1/8 w.
R53 19B800607P104 Metal film: 100K ohms ±5%, 1/8 w.
R54 19B800607P223 Metal film: 22K ohms ±5%, 1/8 w.
R55 19B800607P104 Metal film: 100K ohms ±5%, 1/8 w.
R56 19B800607P181 Metal film: 180 ohms ±5%, 1/8 w.
R57 19B800607P821 Metal film: 820 ohms ±5%, 1/8 w.
R58
thru
R66
19B800607P102 Metal film: 1K ohms ±5%, 1/8 w.
R67 19B800607P104 Metal film: 100K ohms ±5%, 1/8 w
R68 19B800607P102 Metal film: 1K ohms ±5%, 1/8 w.
R69 19B800607P101 Metal film: 100 ohms ±5%, 1/8 w.
R70
thru
R74
19B800607P102 Metal film: 1K ohms ±5%, 1/8 w.
R75 19B800607P391 Metal film: 390 ohms ±5%, 1/8 w.
R76 19B800607P100 Metal film: 10 ohms ±5%, 1/8 w.
R77 19B800607P102 Metal film: 1K ohms ±5%, 1/8 w.
R78 19B800607P392 Metal film: 3.9K ohms ±5%, 1/8 w.
R79 19B800607P272 Metal film: 2.7K ohms ±5%, 1/8 w.
R80 19B800607P750 Metal film: 75 ohms ±5%, 1/8 w.
R81 19B800607P121 Metal film: 120 ohms ±5%, 1/8 w.
- - - - - -INTEGRATED CIRCUITS - - - - - -
U1 344A3740P1 Silicon, bipolar.
U2 19A705927P1 Silicon, bipolar.
U3 19A149980P2 Linear: Osc./Mixer/IF/Det./Amp.; sim to
MC3372D.
U4
and
U5
19A704125P1 Linear: Quad Comparator; sim to LM339D.
U6
and
U7
19A701789P5 Linear:Quad Op Amp; sim to LM224D.
U8 19A704971P10 Voltage regulator: 8 Vdc;sim to
MC78M08CDT.
- - - - - - - - VARIABLE RESISTOR - - - - - -
VR1 19B800779P12 Variable resistor: 22k ohms, 0.1 w;sim to
Murata RGV4E223.
*COMPONENTS, ADDED, DELETED OR CHANGED BY PRODUCTION CHANGES
VHF RECEIVER RF MODULE
19D902783G1
ISSUE 2
SYMBOL PART NO. DESCRIPTION
- - - - - MISCELLANEOUS - - - -
2 19D902508P1 Chassis.
3 19D902509P1 Cover.
4 19D902555P1 Handle.
6 19A702381P506 Screw, thread forming: TORX, No.M3.5 - 0.6
X 6.
7 19A702381P513 Screw, thread forming: TORX, No.M3.5 - 0.6
X 13.
11 19A702381P508 Screw, thread forming: No.3.5-0.6 x 8.
Receiver IF Board
19D902494G1
- - - - - - - - - CAPACITORS - - - - - - - - - - -
C1 19A702052P14 Ceramic: 0.01 µF ±10%, 50 VDCW.
C2 19A702236P52 Ceramic: 120 pF, ±5%, 50 VDCW.
C3 19A702236P49 Ceramic: 91 pF, ±5%, 50 VDCW.
C4 19A702052P14 Ceramic: 0.01 µF ±10%, 50 VDCW.
C5
thru
C7
19A702052P26 Ceramic: 0.1 µF ±10%, 50 VDCW.
C8
thru
C10
19A702052P14 Ceramic: 0.01 µF ±10%, 50 VDCW.
C11
thru
C13
19A702052P26 Ceramic: 0.1 µF ±10%, 50 VDCW.
C14
and
C15
19A702052P14 Ceramic: 0.01 µF ±10%, 50 VDCW.
C16
thru
C18
19A702052P26 Ceramic: 0.1 µF ±10%, 50 VDCW.
C19 19A702052P14 Ceramic: 0.01 µF ±10%, 50 VDCW.
C20
and
C21
19A702061P47 Ceramic: 51 pF ±5%, 50 VDCW, temp coef 0
±30 PPM.
C22 19A702061P1 Ceramic: 1 pF ±0.5 pF, 50 VDCW.
C23
thru
C25
19A702052P26 Ceramic: 0.1 µF ±10%, 50 VDCW.
C26 19A702061P33 Ceramic: 27 pF ±5%, 50 VDCW, temp coef 0
±30 PPM/°C.
C27 19A702052P26 Ceramic: 0.1 µF ±10%, 50 VDCW.
C28 19A702052P5 Ceramic: 1000 pF ±10%, 50 VDCW.
C29 19A705205P5 Tantalum: 6.8 µF, 10 VDCW; sim to Sprague
293D.
C30 19A705205P2 Tantalum: 1 µF, 16 VDCW; sim to Sprague
293D.
C31 19A705205P12 Tantalum: .33 µF, 16 VDCW; sim to
Sprague 293D.
C32
thru
C34
19A702052P26 Ceramic: 0.1 µF ±10%, 50 VDCW
SYMBOL PART NO. DESCRIPTION
C35 19A705205P2 Tantalum: 1 µF, 16 VDCW;sim to Sprague 293D.
C36 19A705205P5 Tantalum: 6.8 µF, 10 VDCW;sim to Sprague
293D.
C37 19A705205P2 Tantalum: 1 µF, 16 VDCW;sim to Sprague 293D.
C38
thru
C40
19A702061P89 Ceramic: 1500 pF ±5%, 50 VDCW, temp coef 0
±30 PPM.
C41 19A702052P22 Ceramic: 0.047 µF ±10%, 50 VDCW.
C42
and
C43
19A702061P77 Ceramic: 470 pF ±5%, 50 VDCW, temp coef 0
±30 PPM.
C44 19A702052P26 Ceramic: 0.1 µF ±10%, 50 VDCW.
C45
thru
C52
19A702052P14 Ceramic: 0.01 µF ±10%, 50 VDCW.
C53 19A705205P12 Tantalum: .33 µF, 16 VDCW;sim to Sprague
293D.
C54
thru
C58
19A702052P14 Ceramic: 0.01 µF ±10%, 50 VDCW.
C59 19A702052P5 Ceramic: 1000 pF ±10%, 50 VDCW.
C60 19A702052P14 Ceramic: 0.01 µF ±10%, 50 VDCW.
C61 19A702052P5 Ceramic: 1000 pF ±10%, 50 VDCW.
C62
thru
C67
19A702052P14 Ceramic: 0.01 µF ±10%, 50 VDCW.
C68 19A702052P5 Ceramic: 1000 pF ±10%, 50 VDCW.
C69
and
C70
19A702052P14 Ceramic: 0.01 µF ±10%, 50 VDCW.
C71
and
C72
19A702052P26 Ceramic: 0.1 µF ±10%, 50 VDCW.
C74 19A702061P49 Ceramic: 56 pF ±5%, 50 VDCW, temp coef 0
±30 PPM.
- - - - - - - - - - - - DIODES - - - - - - - - - - - -
CR1 19A703595P10 Optoelectronic: Red LED in right angle housing;
sim to HP HLMP-1301-010.
D1 19A700083P105 Zener: 8.2V; sim to BZX84-C8V2.
- - - - - - - - - - - FILTERS - - - - - - - - - - - -
FL1 19A702171P3 Bandpass Filter: Fc = 455 kHz, 6dB BW = ±7.5
kHz; sim to Murata CFU455E2.
J1 19A115938P24 Connector, receptacle.
- - - - - - - - - - - JACKS - - - - - - - - - - - - -
J2 19B801587P7 Connector, DIN: 96 male contacts, right angle
mounting; sim to AMP 650887-1.
- - - - - - - - - - -INDUCTORS - - - - - - - - - - -
L1
and
L2
19A700021P13 Coil, fixed: 470 nH.
L3
thru
L7
19A705470P35 Coil, fixed: 6.8 µH.
L8 19A705470P24 Coil, fixed:820 nH.
L9 19A700021P17 Coil, fixed: 1 µH.
SYMBOL PART NO. DESCRIPTION
- - - - - - - - TRANSISTORS - - - - - - - - -
Q1
and
Q2
19A704708P2 Silicon, NPN: sim to NEC 2SC3356.
Q3
thru Q5 19A700076P2 Silicon, NPN: sim to MMBT3904, low profile.
Q6 19A702524P2 N-Type, field effect.
- - - - - - - - - RESISTORS - - - - - - - - - - -
R1 19B800607P510 Metal film: 51 ohms ±5%, 1/8 w.
R2 19B800607P820 Metal film: 82 ohms ±5%, 1/8 w.
R3 19B800607P103 Metal film: 10K ohms ±5%, 1/8 w.
R4 19B800607P102 Metal film: 1K ohms ±5%, 1/8 w.
R5 19B800607P103 Metal film: 10K ohms ±5%, 1/8 w.
R6 19A702931P141 Metal film: 261 ohms ±1%, 200 VDCW,
1/8 w.
R7 19B800607P103 Metal film: 10K ohms ±5%, 1/8 w.
R8 19B800607P102 Metal film: 1K ohms ±5%, 1/8 w.
R9 19B800607P103 Metal film: 10K ohms ±5%, 1/8 w.
R10 19B800607P330 Metal film: 33 ohms ±5%, 1/8 w.
R11 19B800607P102 Metal film: 1K ohms ±5%, 1/8 w.
R12 19B800607P103 Metal film: 10K ohms ±5%, 1/8 w.
R13 19B800607P104 Metal film: 100K ohms ±5%, 1/8 w.
R14 19B800607P103 Metal film: 10K ohms ±5%, 1/8 w.
R15 19B800607P182 Metal film: 1.8K ohms ±5%, 1/8 w.
R16 19A702931P369 Metal film: 51.1K ohms ±1%, 200 VDCW, 1/8
w.
R17 19A702931P261 Metal film: 4220 ohms ±1%, 200 VDCW, 1/8
w.
R18 19A702931P369 Metal film: 51.1K ohms ±1%, 200 VDCW, 1/8
w.
R19 19B800607P822 Metal film: 8.2K ohms ±5%, 1/8 w.
R20 19B800607P392 Metal film: 3.9K ohms ±5%, 1/8 w.
R21
and
R22
19B800607P272 Metal film: 2.7K ohms ±5%, 1/8 w.
R23 19B800607P332 Metal film: 3.3K ohms ±5%, 1/8 w.
R24 19B800607P182 Metal film: 1.8K ohms ±5%, 1/8 w.
R25 19B800607P392 Metal film: 3.9K ohms ±5%, 1/8 w.
R26 19B800607P272 Metal film: 2.7K ohms ±5%, 1/8 w.
R27 19B800607P102 Metal film: 1K ohms ±5%, 1/8 w.
R28 19B800607P272 Metal film: 2.7K ohms ±5%, 1/8 w.
R29 19B800607P822 Metal film: 8.2K ohms ±5%, 1/8 w.
R30 19B800607P153 Metal film: 15K ohms ±5%, 1/8 w.
R31 19B800607P103 Metal film: 10K ohms ±5%, 1/8 w.
R32
and
R33
19B800607P104 Metal film: 100K ohms ±5%, 1/8 w.
R34 19B800607P153 Metal film: 15K ohms ±5%, 1/8 w.
R35 19B800607P331 Metal film: 330 ohms ±5%, 1/8 w.
R36
and
R37
19B800607P104 Metal film: 100K ohms ±5%, 1/8 w.
R38 19B800607P102 Metal film: 1K ohms ±5%, 1/8 w.
LBI-38643C
7

PARTS LIST & PRODUCTION CHANGES
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. A - 19D902494G1, 25 kHz IF Module Board
To improve performance in high temperature environments and to
eliminate Audio Level drifting, changed voltage regulator U8 and vari-
able resistor VR1.
U8 was: 19A704971P11, 8 Vdc;sim to MC78L08ACD.
VR1 was: 19A705496P5 20K ohms 0.1w; sim to Murata RGV4E203.
Rev. B - 19D902494G1, 25 kHz IF Module Board
To change Squelch Driver operation to allow compatibility with GETC,
changed resistors R56, R57, and R69.
R56 was: 19B800607P182 Metal film: 1.8K ohms ±5%, 1/8 w.
R57 was: 19B800607P822 Metal film: 8.2K ohms ±5%, 1/8 w.
R69 was: 19B800607P102 Metal film: 1K ohms ±5%, 1/8 w.
SYMBOL PART NO. DESCRIPTION
- - - - - - - - - - -CRYSTALS - - - - - - - - -
Y1 19A149974G7 Filter, crystal: Fc = 21.4 MHz, 3 dB BW =
15.0 kHz.Insertion loss = 2.0 dB max.
Y2 19A149974G8 Filter, crystal: Fc = 21.4 MHz, 3 dB BW =
15.0 kHz.Insertion loss = 3.0 dB max.
Y3 19A702284G5 Quartz crystal unit:20.945000 MHz ±10 ppm
@ 25°C.
Y4 19A149976P1 Fixed: 455 kHz.
LBI-38643C
8

IC DATA
U4 & U5
19A704125P1
Quad Comparator
U6 & U7
19A701789P4
Quad Op-Amp
U8
19A704971P10
Voltage Regulator
U3
19A149980P2
FM Receiver
U1
344A3740P1
Silicon Bipolar IC
U2
19A705927P1
Silicon Bipolar IC
LBI-38643C
9

ASSEMBLY DIAGRAM
MAINTENANCE MANUAL
FOR
UHF TRANSMITTER SYNTHESIZER MODULE
19D902780G3, G6 - G10
LBI-38671H
TABLE OF CONTENTS
Page
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
GENERAL SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
CIRCUIT ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
VOLTAGE CONTROLLED OSCILLATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
FREQUENCY DOUBLER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
RF AMPLIFIERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
REFERENCE BUFFER AMPLIFIER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
PRESCALER AND SYNTHESIZER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
LOOP BUFFER AMPLIFIERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
AUDIO FREQUENCY AMPLIFIER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
VOLTAGE REGULATORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
LOGIC CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
TEST PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
ALIGNMENT PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
PRODUCTION CHANGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
IC DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
OUTLINE DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
ASSEMBLY DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Back Cover
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.
E
UHF TRANSMITTER
SYNTHESIZER MODULE
19D902780G3, G6 - G10
(19D902780, Sh. 1, Rev. 5)

DESCRIPTION
The principle function of the Transmitter Synthesizer Module
is to provide the RF excitation for input to the MASTR III
station power amplifier. The output of the synthesizer is a
frequency modulated signal at the desired frequency. The mod-
ule contains the following functional blocks:
•A voltage controlled oscillator.
•Frequency Doubler (Multiplier).
•A chain of integrated circuit RF Amplifiers.
•A reference buffer amplifier.
•Dual modulus prescaler and synthesizer integrated
circuits.
•Loop amplifiers and passive loop filter.
•An audio amplifier and a pre-modulation integrator.
•IC voltage regulators for +5 and -5 Vdc. A discrete
component regulator for +8 Vdc, and an Opera-
tional Amplifier regulator for +4 Vdc.
•Logic circuitry: address decoder,input signal gates,
and a lock indicator circuit.
CIRCUIT ANALYSIS
VOLTAGE CONTROLLED OSCILLATOR
Transistor Q1 and associated circuitry comprise a low noise
Voltage Controlled Oscillator (VCO). Inductor L1 and asso-
ciated capacitors form the oscillator resonant circuit (tank).
The noise characteristic of this oscillator is dependent on the
Q of this resonant circuit. The components used in the tank
are specified to have especially high Q. Diode D1 aids in
setting the bias point for low noise operation. (Any field
replacement of oscillator parts should use identical parts).
VariableCapacitorC10setsthe fixedcapacitanceinthetank,
and therefore sets the frequency range over which the oscil-
lator can be voltage tuned.
The oscillator frequency is voltage tuned by the signal ap-
plied through R5 and L5 to the two varicap diodes D2 and
D3. Additionally, audio modulation is applied as an AF
voltage to the two varicap diodes. This RF voltage varies the
oscillator frequency at an audio rate (i.e., it frequency modu-
lates the oscillator). Low frequency audio is applied along
with the varicap control voltage through R5 and L5 while
high frequency audio (MOD) is applied via C16.
Resistors R6 through R9 provide a two volt negative bias on
the varicap diodes.
Transistors Q101 and Q102 and associated circuitry form the
oscillator enable switch. This switch allows the station con-
trol circuitry to turn the VCO ON or OFF via the ANT_REL
line. Setting the ANT_REL line to a logic low causes Q102
to conduct. The five (5) volt output at Q102 collector
(OSCON) enables the fault indicator gates, U705-3 and
U705-4, and turns on Q101. Q101 starts to conduct, provid-
ing a ground path for Q1. This turns ON the VCO.
FREQUENCY DOUBLER
Transistors Q801 and Q802 form a buffer stage to drive
transistormultiplier Q803.The buffer isolatesVCO Q1from
loading effects which could degrade oscillator loaded Q and
hence noise performance. Transistor multiplier Q803 is
tuned to pass the second harmonic of the VCO output and
serves as a frequency doubler. Tank elements L802, C812-
C814 and L803 form a resonant circuit and matching net-
work to drive resistive splitter R201-R204.
RF AMPLIFIERS
The RF chain begins with resistive splitter R201-R204 and
R216-R218. The output of the splitter at R203 is attenuated
by 10 dB and provides impedance matching helical filter
FL201, which is tuned to pass the fundamental while reject-
ing harmonics by approximately40 dB.The output of FL201
is fed thru resistive pad R205-R207 to MMIC Amplifier
U201 which operates in compression. U201 drives output
amplifier U202 into compression. The output amplifier is
followed by a bandpass filter (C208-C210, L203-L205) and
resistive attenuators (R210-R215). The final output at the
front panel BNC Connector (J2) is nominally 11.5 dBm, and
drives the station Power Amp.
The other output of the resistivesplitter at R218 is attenuated
by 20 dB and drives buffer amp U203 into compression.
U203 drives the synthesizer prescaler providing a feedback
signal for the synthesizer phase locked loop.
REFERENCE BUFFER AMPLIFIER
TransistorQ401andassociatedcomponentscompriseabuff-
eramplifierforthereferenceoscillatorsignal.(Thereference
oscillator signal is produced by the receiver synthesizer
module of a MASTR III station.) The 0 dBm reference
oscillator signal is fed through the front panel BNC connec-
tor J1. Resistor R405 provides a 50 ohm load to the reference
oscillator. The output of the Reference Buffer Amplifier is
fed directly to the synthesizer integrated circuit. The output
level at TP9 is approximately 3 volts peak to peak.
Copyright © June 1992, Ericsson GE Mobile Communications, Inc.
TABLE 1 - GENERAL SPECIFICATIONS
ITEM SPECIFICATION
FREQUENCY RANGE 450-470 MHz (G3)
425-450 MHz (G7)
403-430 MHz (G6)
380-400 MHz (G8)
470-494 MHz (G9)
490-512 MHz (G10)
CHANNEL SPACING 6.25 kHz
RF POWER OUT (50 Ohm load) 10 to 13 dBm
(10 to 20 mW)
RF HARMONICS < -30 dBc
NON-HARMONIC SPURS
1 to 200 MHz < - 90 dBc
200 MHz to 1 GHz < - 60 dBc
CARRIER ATTACK TIME <25 mSec
REFERENCE INPUT
input level 0 dBm ±1.5dB
input impedance 50 Ohm
frequency 5 to 17.925 MHz (must be integer divisible by
channel spacing)
MODULATION SENSITIVITY 5 kHz peak dev/1 Vrms, Adjustable
AF INPUT IMPEDANCE 600 Ohm
AF RESPONSE
10 Hz ±1.5 dB
1000 Hz0 dB reference
3 kHz ±1.5 dB
10 Hz SQUARE WAVE MODULATION <10%
Sq wave droop
HUM & NOISE -55 dB
POWER REQUIREMENTS 13.8 Vdc @ 275 mA
-12.0 Vdc @ 10 mA
This manual is published by EricssonInc., without any warranty. Improvements and changes to this manual necessitated by typographical errors, inaccuracies of current information, or improvements to programs
and/or equipment, may be made by Ericsson Inc., at any time and without notice. Such changes will be incorporated into new editions of this manual. No part of this manual may be reproduced or transmitted in any
form or by any means, electronic or mechanical, including photocopying and recording, for any purpose, without the express written permission of Ericsson Inc.
LBI-38671H
1

PRESCALER AND SYNTHESIZER
Integrated circuit U402 is the heart of the synthesizer. It
contains the necessary frequency dividers and control cir-
cuitry to synthesize output frequencies by the technique of
dual modulus prescaling. U402 also contains an analog
sample and hold phase detector and a lock detector circuit.
Within the synthesizer (U402) are three programmable di-
viders which are loaded serially using the CLOCK, DATA,
and ENABLE inputs (pins 11, 12, and 13 respectively). A
serial data stream (DATA) on pin 12 is shifted into internal
shift registers by low to high transitions on the clock input
(CLOCK) at pin 11. A logic high (ENABLE) on pin 13 then
transfers the program information from the shift registers to
the divider latches.
The reference signal is applied to U402 pin 2 and divided by
the "R" divider. This divides the reference signal down to a
divided reference frequency (Fr). The typical reference fre-
quency is 12.8 MHz and the typical divided reference fre-
quency is 6.25 kHz providing for synthesizer steps of 6.25
kHz for use with both 12.5 kHz and 25 kHz channel spacing.
Other channel spacings are possible by providing proper
programming.
The "A" and "N" dividers process the loop feedback signal
provided by the VCO (by way of the dual modulus prescaler
U401). The output of the "N" divider is a divided version of
the VCO output frequency (Fv).
Synthesizer U402 also contains logic circuitry to control the
dual modulus prescaler U401. If the locked synthesizer
output frequency is 450 MHz. The prescaler output nomi-
nally will be equal to 3.515625 MHz (450 MHz/128). This
frequency is further divided down to Fvby the "N" divider
in U402. Fv is then compared with Frin the phase detector
section.
The phase detector output voltage is proportional to the
phase difference between Fvand Fr. This phase detector
output serves as the loop error signal. This error signal
voltage tunes the VCO to whatever frequency is required to
keep Fvand Frlocked (in phase).
LOOP BUFFER AMPLIFIERS AND LOOP
FILTER
The error signal provided by the phase detector output is
buffered by operational amplifiers (op-amp) U501A and
U501B. The audio modulation signal from U601B is also
applied to the input of U501B. The output of U501B is the
sum of the audio modulation and the buffered error signal.
The output of the second buffer (U501B) is applied to a loop
filter consisting of R506, R507, R508, C505 and C506. This
filter controls the bandwidth and stability of the synthesizer
loop. The UHF transmitter synthesizer has a loop bandwidth
of only several Hertz. This is very narrow, resulting in an
excessively long loop acquisition time. To speed acquisition,
switches U502A and U502C bypass the filter circuit when-
ever an ENABLE pulse is received by the Input Gates.
AUDIO FREQUENCY AMPLIFIER
The transmitter synthesizer audio input line is fed to U601A.
U601A is configured as a unity gain op-amp. Resistor R601
sets the 600 ohm input impedance of this amplifier. (NOTE:
Data for digital modulation is fed to the synthesizer through
the audio input line).
The amplifier output is split into two components and fed to
two variable resistors VR601 and VR602. VR601 sets the
level in the low frequency audio path and VR602 sets the
level in the high frequency audio path. (There is no clear
break between the low and high frequency ranges. All voice
frequencies are within the high frequency range. The low
frequency range contains low frequency data components).
The wiper of VR601 (low frequency path) connects to the
input of U601B, the pre-modulation integrator. U601B per-
forms the function of a low-pass filter and integrator. The
integrator output is summed with the PLL control voltage at
the input of loop buffer amplifier U501B. This integrated
audio signal phase modulates the VCO. The combination of
pre-integration and phase modulation is equivalent to fre-
quency modulation.
The wiper of VR602 (high frequency path) is connected to
the modulation input of the VCO through C16.
VOLTAGE REGULATORS
U301 and U303 are monolithic voltage regulators (+5 Vdc
and -5 Vdc respectively). These two voltages are used by
synthesizer circuitry. The +5 V regulator output is also used
as a voltage reference for the +8 Vdc discrete regulator
circuit.
U302A, Q302 and associated circuitry comprise the +8 volt
regulator. Most module circuitry is powered from the +8 volt
line. The regulator is optimized for especially low noise
performance. This is critical because the low noise VCO is
powered by the +8 volt line.
The +8 Vdc line also feeds the +4 Vdc regulator, U302B and
associated resistors. The +4 Vdc regulator provides a bias
voltage for several op-amps in the module.
Figure 1 - Block Diagram
LBI-38671H
2

LOGIC CIRCUITS
Logic circuitry (other than that inside the synthesizer IC -
U402) consists of the following:
•An address decoder
•Input gates and level shifters
•Lock Indicator circuitry
The address decoder, U702, enables the Input Gates when the
A0, A1, and A2 input lines receive the proper logic code (110
for the transmitter synthesizer). After receiving the proper
code, Y3 (U702-12) sends a logic low signal to U701C. U701C
acts as an inverter and uses the logic high output to turn on
Input Gates U701A, U701B, and U701D. The Input Gates
allow the clock, data and enable information to pass on to the
synthesizer via the level shifters. The Level Shifter Transistors
Q701, Q702 and Q703 convert the 5 volt gate logic level to the
8 volt logic level required by the synthesizer U402.
The Fault Indicator circuitry indicates when the synthesizer is
in an out-of-lock condition. The fault detector latches, U705A
and U705B are reset by the enable pulse during initial loading
of data into the synthesizer. If at any time afterwards the lock
detector signal (LD) goes low, the high output of U705B will
cause the output of gates U705C and U705D to go low. The
low output from U705C causes Q704 to conduct turning on the
front panel LED (CR701). The output of U705D (FLAG) is
connected to J3-13C for external monitoring of theSynthesizer
Module. A logic low on the FLAG line indicates an out-of-lock
condition.
MAINTENANCE
RECOMMENDED TEST EQUIPMENT
The following test equipment is required to test the synthesizer
Module:
1. RF signal source for 12.8 MHz, 0 dBm reference (in-
cluded with item 10)
2. AF Generator or Function Generator
3. Modulation Analyzer; HP 8901A, or equivalent, or a
UHF receiver
4. Oscilloscope; 20 MHz
5. DC Meter; 10 meg ohm (for troubleshooting)
6. Power Supply; 13.8 Vdc @ 350 mA
12.0 Vdc @ 25 mA
7. Spectrum Analyzer; 0-1 GHz
8. Frequency Counter; 10 MHz - 500 MHz
9. Personal Computer (IBM PC compatible) to load fre-
quency data
10. Service Parts Kit, (TQ-0650), (includes software for
loading frequency data)
TEST PROCEDURE
(Steps 5, 6, and 7 can be done using a modulation analyzer
or UHF receiver with 750 µs de-emphasis switchable in or
out.
1. Lock synthesizer at 470.0 (G3), 430 (G6), 450 (G7),
400(G8),494(G9)or512(G10)MHzusingsoftware
provided in the service parts kit.
Verify lock (flag = high).
Verify front panel LED is off.
2. Measure output frequency.
Verify frequency = 470.0000 (G3), 425.000
(G6) or 450.000 (G7) MHz, 400.000 (G8),
494.000 (G9) or 512.000 (G10) ±200 Hz.
3. Measure harmonic content.
Verify 2nd harmonic is < -30 dBc.
4. Measure RF power output into 50 ohm load.
Verify 10 to 13 dBm (10 to 20 mW).
5. MeasureAF distortionwith standard modulatingsig-
nal input.
Verify <2.5%.
6. MeasureHumandNoiserelativeto0.44kHzaverage
deviation, (de-emphasis on).
Verify < -55dB
7. Measure AF response at 300 Hz, 1 kHz (ref) and 3
kHz, (de-emphasis off).
Verify within ±1.5 dB with respect to 1 kHz
reference.
8. Verify lock at different frequencies.
a. Lock synthesizer at 380 (G8), 450 (G3), 403
(G6), 425 (G7), 470 (G9) or 492 (G10) MHz.
Verify LED is off.
b. Lock synthesizer at 385 (G8), 455 (G3), 408.5
(G6), 430 (G7), 476 (G9) or 497 (G10) MHz.
Verify LED is off.
c. Lock synthesizer at 395 (G8), 465 (G3), 419.5
(G6), 445 (G7), 488 (G9) or 507 (G10) MHz.
Verify LED is off.
d. Lock synthesizer at 400 (G8), 470 (G3), 425
(G6), 450 (G7), 494 (G9) or 512 (G10) MHz.
Verify LED is off.
ALIGNMENT PROCEDURE
1. Apply +13.8 Vdc and -12 Vdc. Verify the current
drain on the 13.8 volt supply is, <300mA and the
current drain on the -12 volt supply is <20 mA.
2. Lockthesynthesizerat380(G8),450(G3),403(G6),
425 (G7), 470 (G9) or 492 (G10) MHz. Adjust trim-
mer C1O until Vtest (23A) reads 2.5 (G3, G8), 2.0
(G6, G7, G9) or 3.0 (G10) V ±0.05V.
3. Locksynthesizerat460.0(G3),390.0(G8),414(G6)
or 437.5 (G7), 482 (G9) or 502 (G10) MHz for the
following three adjustments.
•Set VR602 for 4.5 kHz peak deviation with a stand-
ard modulating signal applied to the audio input.
•Set VR601 for 4.5 kHz peak deviation with 1.0
Vrms, 10 Hz (or 7 Hz for G3) sine wave audio
applied to module AF input.
•Apply a 10 Hz 1.4 Vpk square wave to module AF
input. Adjust VR601 slightly for the flattest de-
modulated square wave using a modulation ana-
lyzer or receiver (no de-emphasis) and an
oscilloscope.Themaximum netvariation involtage
over 1/2 cycle is 5%.
TROUBLESHOOTING
A troubleshooting guide is provided showing typical meas-
urements at the various test points.
This adjustment is critical for EDACS application
and must be reset at customer frequency.
NOTE
SERVICE NOTES
The following service information applies when
aligning, testing, or troubleshooting the TX Synthe-
sizer:
•Standard Modulating Signal = 1 kHz sinusoidal
voltage, 0.6 Vrms at the module input terminals
(600 ohm Rin).
•Logic Levels:
Logic 1 = high = 4.5 to 5.5 Vdc
Logic 0 = Low = 0 to 0.5 Vdc
•Transmitter Synthesizer Address = A0 A1 A2 =
110
•Synthesizer data input stream is as follows:
14-bit "R" divider most significant bit
(MSB) = R13 through "R" divider least sig-
nificant bit (LSB) = R0
10-bit "N" divider MSB = N9 through "N"
divider LSB = N0
7-bit "A" divider MSB = A6 through "A"
divider LSB = A0
Single high Control bit (last bit)
Latched When Control Bit = 1
DATA ENTRY FORMAT
Latched When
Control Bit = 1
Data in ➞Last A0 A6 N0 N9 R0 R13 ➞
Bit LSB – – – – – MSB LSB – – – – MSB LSB
For the transmitter synthesizer, 5 kHz chan-
nel spacing
R = 2560
N = integer part of (frequency in kHz)/(320)
A = (frequency in kHz)/(5) - 64*N
All numbers must be converted to binary.
•ANT_REL line must be logic low (0V) in order to
lock synthesizer.
•Synthesizer lock is indicated by the extinguishing
of the front panel LED indicator and a logic high
on the fault flag line (J3 pin 13C).
•Always verify synthesizer lock after each new data
loading.
Control B
LBI-38671H
3

PARTS LIST
SYMPTOM CHECK
(CORRECT READINGS SHOWN) INCORRECT READING INDICATES DEFECTIVE COMPONENT
SYNTHESIZER FAILS TO LOCK Check DC voltages
+5 V @ U301 Pin 1
+8 V @ Q301 collector
-5 V @ U303 Pin 1
U301 or associated components
U302, Q301, Q302 or associated
components
U303 or associated components
Check 12.8 MHz reference signal
3V P-P, 12.8 MHz @ U402 Pin 2 No reference signal to front panel BNC or Q401
Check oscillator signal
11.5 ±1.5 dBm 435 to 485 MHz at
front panel BNC Proceed to "Low/No RF output" below
Check prescaler output
IV P-P, 3.5 MHz @ U401 Pin 4 U202, U401
Check CLOCK, DATA, ENABLE
While loading frequency data into
synthesizer Check 8V logic signals
@ Pins 11, 12, 13 of U402
Wrong address or
U701, U702, Q701, Q702, Q703
Check Phase detector output
6.25 kHz random signal @ U501
Pin 7 U402, U501
Low/No RF Output Check oscillator
LESS than 0.5 Vdc @ collector of
Q101 Synthesizer not keyed (low on ANT relay line) or Q101, Q102
Check RF chain
No Modulation Check AF amplifier
Apply IV, 1 kHz signal to
TX/Audio/Hi U601
Check IV signal @ U601 Pin 1
TROUBLESHOOTING GUIDE UHF TRANSMITTER SYNTHESIZER MODULE
19D902780G3, G6 - G10
ISSUE 9
*COMPONENTS, ADDED, DELETED OR CHANGED BY PRODUCTION CHANGES
SYMBOL PART NO. DESCRIPTION
TRANSMITTER SYNTHESIZER BOARD
19D902779G3, G6 - G10
- - - - - - - - - MISCELLANEOUS - - - - - - - - -
2 19D902508P4 Chassis.
3 19D902509P2 Cover.
4 19D902555P1 Handle.
6 19A702381P506 Screw, thread forming: TORX, No.M3.5-.6 x 6.
7 19A702381P513 Screw, thread forming: TORX, No.M3.5 - 0.6 X 13.
11 19A702381P508 Screw, thd. form: No. 3.5-0.6 x 8.
12 19D902824P1 Casting.
- - - - - - - - - - CAPACITORS - - - - - - - - -
C1 19A702236P25 Ceramic: 10 pF + or -.5 pF, 50 VDCW, temp coef
+ or -30 PPM/°C.
C2 19A702236P32 Ceramic: 18 pF + or -5%, 50 VDCW, temp coef 0 +
+ or or -30 PPM
C3 19A702236P28 Ceramic: 12 pF + or - 5%, 50 VDCW, temp coef 0
+ or -30 PPM.
C4 19A702236P1 Ceramic: 0.5 pF + or - pF, temp coef 0
+ or - PPM/°C.(Used in G8).
C4 19A702236P8 Ceramic: 1.5 pF + or -.25 pF, 50 VDCW.
(Used in G3, G6, G7)
C4
and
C5
19A702236P17 Ceramic: 4.7 pF + or -0.5%, 50 VDCW, temp coef 0
+ or -60 PPM. (Used in G9).
C4 19A702236P11 Ceramic: 2.7 pF + or - .25 pF, 50 VDCW, temp coef 0
+ or -30 PPM/°C. (Used in G10).
C5 19A702236P17 Ceramic: 4.7 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM. (Used in G3 & G10).
C5 19A702236P17 Ceramic: 4.7 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM. (Used in G6 & G8).
C5 19A702236P15 Ceramic: 3.9 pF + or -.25 pF, 50 VDCW, temp
+ or -30 PPM/°C. (Used in G7).
C6 19A702236P28 Ceramic: 12 pF + or - 5%, 50 VDCW, temp coef 0
+ or -30 PPM.(Used in G8 & G3).
C6 19A702236P30 Ceramic: 15 pF + or -5%, 50 VDCW, temp coef 0 +
or -30 PPM/°C. (Used in G6 & G7).
*C6 19A702236P28 Ceramic: 12 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM/°C.(Used in G9 & G10).
C7 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM/°C.
C8 19A702052P14 Ceramic: 0.01 uF + or - 10%, 50 VDCW.
C9 19A705205P6 Tantalum: 10 uF, 16 VDCW;sim to Sprague 293D.
C10 19A134227P5 Variable: 1.5 to 14 pF, 100 VDCW.
C11 19A705205P2 Tantalum: 1 uF, 16 VDCW;sim to Sprague 293D.
C12 19A702052P14 Ceramic: 0.01 uF + or - 10%, 50 VDCW.
C13 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0
and + or -30 PPM/°C.
C14
*C15 19A700004P6 Metallized polyester: 4.7 uF + or - 10%, 63 VDCW.
*C16 19A702052P106 Ceramic: 1500 pF + or -5%, 50 VDCW.
C17 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM/°C.
C18 19A705205P2 Tantalum: 1 uF, 16 VDCW;sim to Sprague 293D.
and
C19
C101 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM/°C.
C102 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.
C103 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM/°C.
SYMBOL PART NO. DESCRIPTION
C201 19A702061P61 Ceramic: 100 pF + or - 5%, 50 VDCW, temp coef 0
+ or - 30 PPM.
C202 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM/°C.
C203 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.
C204 19A702061P61 Ceramic: 100 pF + or - 5%, 50 VDCW, temp coef 0
and + or - 30 PPM.
C205
C206 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM/°C.
C207 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.
C208 19A702236P28 Ceramic: 12 pF + or - 5%, 50 VDCW, temp coef 0
+ or -30 PPM.
C209 19A702236P10 Ceramic: 2.2 pF + or -2.5 pF, 50 VDCW, temp
+ or -30 PPM/°C. (Used in G3, G6, G7, G8).
C209 19A702236P8 Ceramic: 1.5 pF + or -0.25 pF, 50 VDCW, temp
+ or -30 PPM/°C. (Used in G9 & G10).
C210 19A702236P28 Ceramic: 12 pF + or - 5%, 50 VDCW, temp coef 0
+ or -30 PPM.
C211 19A702061P61 Ceramic: 100 pF + or - 5%, 50 VDCW, temp coef 0
and + or - 30 PPM.
C212
C213 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.
C214 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM/°C.
C215 19A702061P61 Ceramic: 100 pF + or - 5%, 50 VDCW, temp coef 0
+ or - 30 PPM.
C301 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM/°C.
C302 19A702052P14 Ceramic: 0.01 uF + or - 10%, 50 VDCW.
C303 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.
and
C304
C305 19A705205P7 Tantalum: 10 uF, 25 VDCW; sim to Sprague 293D.
C306 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.
C307 19A705205P6 Tantalum: 10 uF, 16 VDCW; sim to Sprague 293D.
C308 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0
and + or -30 PPM/°C.
C309
C310 19A705205P6 Tantalum: 10 uF, 16 VDCW; sim to Sprague 293D.
C311 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.
C312 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM/°C.
C313 19A705205P6 Tantalum: 10 uF, 16 VDCW; sim to Sprague 293D.
C401 19A702052P14 Ceramic: 0.01 uF + or - 10%, 50 VDCW.
C402 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM/°C.
C403 19A702052P14 Ceramic: 0.01 uF + or - 10%, 50 VDCW.
thru
C405
C406 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM/°C.
C407 19A702052P14 Ceramic: 0.01 uF + or - 10%, 50 VDCW.
C408 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM/°C.
C409 19A705205P6 Tantalum: 10 uF, 16 VDCW; sim to Sprague 293D.
C410 19A702052P26 Ceramic: 0.1uF + or - 10%, 50 VDCW
C411 19A705205P6 Tantalum: 10 uF, 16 VDCW; sim to Sprague 293D.
C412 19A702052P14 Ceramic: 0.01 uF + or - 10%, 50 VDCW.
C413 19A702052P108 Ceramic: 0.01 uF + or -10%, 50 VDCW.
C414 19A702061P69 Ceramic: 220 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM/°C.
C501 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.
C502 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.
C503 19A702052P33 Ceramic: 0.1 uF + or -10%, 50 VDCW.
LBI-38671H
4

PARTS LIST
SYMBOL PART NO. DESCRIPTION
C504 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM/°C.
C505 19A703684P3 Metalized polyester: 2.2 uF + or - 10$, 50 VDCW.
C506 19A703902P3 Metal: 0.047 uF + or -10%, 50 VDCW.
C507 19A702052P33 Ceramic: 0.1 uF + or -10%, 50 VDCW.
C602 19A705205P6 Tantalum: 10 uF, 16 VDCW; sim to Sprague 293D.
C603 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM/°C.
C604 19A705205P2 Tantalum: 1 uF, 16 VDCW; sim to Sprague 293D.
C605 19A703684P3 Metalized polyester: 2.2 uF + or - 10$, 50 VDCW.
C701 19A702061P61 Ceramic: 100 pF + or - 5%, 50 VDCW, temp coef 0
thru + or - 30 PPM.
C712
C714 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0
and + or -30 PPM/°C.
C715
C801 19A702061P4 Ceramic: 1.8 pF + or - 0.5 pF, 50 VDCW, temp
or - 250 PPM.
C802 19A705205P6 Tantalum: 10 uF, 16 VDCW; sim to Sprague 293D.
C803 19A702052P14 Ceramic: 0.01 uF + or - 10%, 50 VDCW.
and
C804
C805 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM/°C.
C806 19A702061P65 Ceramic: 150 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM/°C.
C807 19A705205P6 Tantalum: 10 uF, 16 VDCW; sim to Sprague 293D.
C808 19A702052P14 Ceramic: 0.01 uF + or - 10%, 50 VDCW.
C809 19A702061P13 Ceramic: 10 pF + or - 5%, 50 VDCW, temp coef 0
+ or - 30 PPM.
C810 19A702052P14 Ceramic: 0.01 uF + or - 10%, 50 VDCW.
C811 19A702061P99 Ceramic: 1000 pF + or -5%, 50 VDCW, temp coef 0
+ or -30 PPM/°C.
C812 19A702061P13 Ceramic: 3.3 pF + or - 0.25 pF, temp
or - 30 PPM/°C.(Used in G8).
C812 19A702061P5 Ceramic: 2.2 pF + or - 0.5 pF, 50 VDCW, temp
or - 120 PPM.(Used in G6, G7, G3).
C813 19A702061P21 Ceramic: 15 pF + or - 5%, 50 VDCW, temp coef 0
and + or - 30 PPM. . (Used in G6, G7, G3).
C814
C813 19A702061P32 Ceramic: 18 pF + or - 5%, 50 VDCW, temp coef 0
and + or - 30 PPM/°C.(Used in G8).
C814
C813 19A702236P28 Ceramic: 12 pF + or - 5%, 50 VDCW, temp coef 0
and + or - 30 PPM. . (Used in G9 & G10).
C814 - - - - - - - - - - - DIODES - - - - - - - - - -
CR701 19A703595P10 Optoelectic: Red LED; sim to HP HLMP-1301-010.
D1 19A705377P1 Silicon, Hot Carrier: sim to MMB0201.(Used in
G40, G3, G6,
D2 19A149674P3 High tuning ratio diode:sim to Toko KV1430.
and
D3 - - - - - - - - - - - FILTERS - - - - - - - - - -
FL201 19A705458P8 Filter: 378-402 MHz; sim to
302MXPR-1785A (Used in G8).
FL201 19A705458P5 Helical, UHF: 424-450 MHz. (Used in G7).
FL201 19A705458P4 Helical, UHF: 403-425 MHz. (Used in G6).
FL201 19A705458P1 Helical, UHF: 450-470 MHz. (Used in G3)
FL201 19A705458P6 Helical, UHF: 492-512 MHz. (Used in G10)
- - - - - - - - - - - JACKS - - - - - - - - - - -
J1 19A115938P24 Connector, receptacle.
and
J2
J3 19B801587P7 Connector, DIN: 96 male contacts, right angle
to AMP 650887-1.
- - - - - - - - - - INDUCTORS - - - - - - - - - -
L1 19C851001P3 Coil, RF: 1 1/2 Turns, sim to Paul Smith
SK-901-1.(Used in G8).
L1 19C851001P2 Coil, RF: sim to Paul Smith SK-901-1.(Used in G6).
SYMBOL PART NO. DESCRIPTION
L1 19C851001P1 Coil, RF: sim to Paul Smith SK901-1.
(Used in G3, G7).
L2 19A705470P28 Coil, Fixed: 1.8 uH; sim to Toko 380LB-1R8M.
(Used in G9 & G10).
L2 19A705470P24 Coil, Fixed:0.82 uH;sim to Toko 380NB-R82M.
thru (Used in G3, G6 - G8).
L5
L10 19C851001P4 Coil, RF. (Used in G9, G10).
L201 19A705470P15 Coil, fixed:0.15uH;sim to Toko 380NB-R15M.
and
L202
L203 19A705470P1 Coil, Fixed: 10 nH; sim to Toko 380NB-10nM.
L204 19A705470P10 Coil, fixed:56 nH;sim to Toko 380NB-56nM.
L205 19A705470P1 Coil, Fixed: 10 nH; sim to Toko 380NB-10nM.
L206 19A705470P15 Coil, fixed:.15uH;sim to Toko 380NB-R15M.
L801 19A705470P2 Coil, Fixed: 12 nH; sim to Toko 380NB-12nM.
thru
L803 - - - - - - - - - - TRANSISTORS - - - - - - - - -
Q1 19A702524P2 N-Type, field effect;sim to MMBFU310.
Q101 19A700076P2 Silicon, NPN: sim to MMBT3904, low profile.
Q102 19A700059P2 Silicon, PNP: sim to MMBT3906, low profile.
Q301 19A134577P2 Silicon, PNP: sim to Phillips BCX51-16.
Q302 19A700076P2 Silicon, NPN: sim to MMBT3904, low profile.
Q401 19A704708P2 Silicon, NPN: sim to NEC 2SC3356.
Q501 19A700076P2 Silicon, NPN: sim to MMBT3904, low profile.
Q701 19A700076P2 Silicon, NPN: sim to MMBT3904, low profile.
thru
Q704
Q801 19A704708P2 Silicon, NPN: sim to NEC 2SC3356.
thru
Q803 - - - - - - - - - - RESISTORS - - - - - - - - - -
R1 19B800607P470 Metal film: 47 ohms + or -5%, 1/8 w.
R2 19B800607P183 Metal film: 18K ohms + or -5%, 1/8 w.
R3 19B800607P680 Metal film: 68 ohms + or -5%, 1/8 w.
R4 19B800607P100 Metal film: 10 ohms + or -5%, 1/8 w.
and
R5
R6 19B800607P824 Metal film: 820K ohms + or -5%, 1/8 w.
R7 19B800607P104 Metal film: 100K ohms + or -5%, 1/8 w.
R8 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.
R9 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w. (Used in G9).
R9 19B800607P681 Metal film: 680 ohms + or -5%, 1/8 w.(Used in G3, G7-G8).
R9 19B800607P152 Metal film: 1.5K ohms + or -5%, 1/8 w. (Used in G6).
R101 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.
R102 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.
R103 19B800607P473 Metal film: 47K ohms + or -5%, 1/8 w.
R104 19B800607P472 Metal film: 4.7K ohms + or -5%, 1/8 w.
R105 19B800607P392 Metal film: 3.9K ohms + or -5%, 1/8 w.
R201 19B800607P180 Metal film: 18 ohms + or -5%, 1/8 w.
and
R202
R203 19B800607P150 Metal film: 15 ohms + or -5%, 1/8 w.
R204 19B800607P101 Metal film: 100 ohms + or -5%, 1/8 w.
R205 19B800607P331 Metal film: 330 ohms + or -5%, 1/8 w.
R206 19B800607P150 Metal film: 15 ohms + or -5%, 1/8 w.
R207 19B800607P331 Metal film: 330 ohms + or -5%, 1/8 w.
R208 19B800607P181 Metal film: 180 ohms + or -5%, 1/8 w.
R209 19B800607P750 Metal film: 75 ohms + or -5%, 1/8 w.
R210 19B800607P331 Metal film: 330 ohms + or -5%, 1/8 w.
*R211 19B800607P120 Metal film: 12 ohms + or -5%, 1/8 w. (Used in G9 & G10)
R211 19B800607P150 Metal film: 15 ohms + or -5%, 1/8 w. (Used in G3, G6-G8)
SYMBOL PART NO. DESCRIPTION
R212 19B800607P331 Metal film: 330 ohms + or -5%, 1/8 w.
and
R213
*R214 19B800607P120 Metal film: 12 ohms + or -5%, 1/8 w. (Used in G9 &
G10)
R214 19B800607P150 Metal film: 15 ohms + or -5%, 1/8 w. (Used in G3,
G6-G8)
R215 19B800607P331 Metal film: 330 ohms + or -5%, 1/8 w.
R216 19B800607P510 Metal film: 51 ohms + or -5%, 1/8 w.
R217 19B800607P220 Metal film: 22 ohms + or -5%, 1/8 w.
R218 19B800607P330 Metal film: 33 ohms + or -5%, 1/8 w.
R219 19B800607P181 Metal film: 180 ohms + or -5%, 1/8 w.
R220 19B800607P104 Metal film: 100K ohms + or -5%, 1/8 w.
R221 19B800607P330 Metal film: 33 ohms + or -5%, 1/8 w.
and
R222
R301 19B800607P100 Metal film: 10 ohms + or -5%, 1/8 w.
thru
R303
R304 19B800607P470 Metal film: 47 ohms + or -5%, 1/8 w.
R305 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.
R306 19B800607P222 Metal film: 2.2K ohms + or -5%, 1/8 w.
R307 19A702931P230 Metal film: 2000 ohms + or -1%, 200 VDCW, 1/8 w.
R308 19A702931P249 Metal film: 3160 ohms + or -1%, 200 VDCW, 1/8 w.
R309 19B800607P471 Metal film: 470 ohms + or -5%, 1/8 w.
R310 19B800607P470 Metal film: 47 ohms + or -5%, 1/8 w.
R311 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.
and
R312
R401 19B800607P330 Metal film: 33 ohms + or -5%, 1/8 w.
R402 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.
R403 19B800607P104 Metal film: 100K ohms + or -5%, 1/8 w.
R404 19B800607P561 Metal film: 560 ohms + or -5%, 1/8 w.
R405 19B800607P510 Metal film: 51 ohms + or -5%, 1/8 w.
R406 19B800607P101 Metal film: 100 ohms + or -5%, 1/8 w.
R407 19B800607P104 Metal film: 100K ohms + or -5%, 1/8 w.
R408 19B800607P100 Metal film: 10 ohms + or -5%, 1/8 w.
R409 19B800607P222 Metal film: 2.2K ohms + or -5%, 1/8 w.
R410 19B800607P392 Metal film: 3.9K ohms + or -5%, 1/8 w.
R411 19B800607P562 Metal film: 5.6K ohms + or -5%, 1/8 w.
R412 19B800607P223 Metal film: 22K ohms + or -5%, 1/8 w.
(Used IN G3, G6, G7, G8).
R412 19B800607P823 Metal film: 82K ohms + or -5%, 1/8 w.
(Used in G9 & G10).
R415 19B800607P100 Metal film: 10 ohms + or -5%, 1/8 w.
R501 19B800607P470 Metal film: 47 ohms + or -5%, 1/8 w.
R502 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.
R503 19B800607P223 Metal film: 22K ohms + or -5%, 1/8 w.
R504 19B800607P150 Metal film: 15 ohms + or -5%, 1/8 w.
R505 19B800607P104 Metal film: 100K ohms + or -5%, 1/8 w.
R506 19B800607P105 Metal film: 1M ohms + or -5%, 1/8 w.
R507 19B800607P183 Metal film: 18K ohms + or -5%, 1/8 w.
(Used IN G3, G6, G7, G8).
*R507 19B800607P393 Metal film: 39K ohms + or -5%, 1/8 w.
(Used in G9 & G10).
R508 19B800607P333 Metal film: 33K ohms + or -5%, 1/8 w.
(Used IN G3, G6, G7, G8).
R508 19B800607P823 Metal film: 82K ohms + or -5%, 1/8 w.
(Used in G9 & G10).
R509 19B800607P473 Metal film: 47K ohms + or -5%, 1/8 w.
R510 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.
R511 19B800607P101 Metal film: 100 ohms + or -5%, 1/8 w.
SYMBOL PART NO. DESCRIPTION
R601 19A702931P176 Metal film: 604 ohms + or -1%, 200 VDCW, 1/8 w.
R602 19B800607P104 Metal film: 100K ohms + or -5%, 1/8 w.
and
R603
R604 19B800607P470 Metal film: 47 ohms + or -5%, 1/8 w.
R605 19B800607P104 Metal film: 100K ohms + or -5%, 1/8 w.
R606 19B800607P680 Metal film: 68 ohms + or -5%, 1/8 w.
R607 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.
R608 19B800607P392 Metal film: 3.9K ohms + or -5%, 1/8 w.
R609 19B800607P472 Metal film: 4.7K ohms + or -5%, 1/8 w.
R610 19B800607P105 Metal film: 1M ohms + or -5%, 1/8 w.
R701 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.
thru
R706
R707 19B800607P472 Metal film: 4.7K ohms + or -5%, 1/8 w.
R708 19B800607P473 Metal film: 47K ohms + or -5%, 1/8 w.
and
R709
R710 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.
thru
R712
R720 19B800607P392 Metal film: 3.9K ohms + or -5%, 1/8 w.
R721 19B800607P562 Metal film: 5.6K ohms + or -5%, 1/8 w.
R722 19B800607P473 Metal film: 47K ohms + or -5%, 1/8 w.
R723 19B800607P391 Metal film: 390 ohms + or -5%, 1/8 w.
R724 19B800607P101 Metal film: 100 ohms + or -5%, 1/8 w.
R801 19B800607P102 Metal film: 1K ohms + or -5%, 1/8 w.
thru
R803
R804 19B800607P101 Metal film: 100 ohms + or -5%, 1/8 w.
thru
R806
R807 19B800607P182 Metal film: 1.8K ohms + or -5%, 1/8 w.
R808 19B800607P103 Metal film: 10K ohms + or -5%, 1/8 w.
R809 19B800607P270 Metal film: 27 ohms + or -5%, 1/8 w.
R810 19B800607P101 Metal film: 100 ohms + or -5%, 1/8 w.
- - - - - - - - INTEGRATED CIRCUITS - - - - - - -
U201 19A705927P1 Silicon, bipolar: sim to Avantek MSA-0611.
U202 344A3907P1 Integrated circuit, MMIC: sim to Avantek MSA-1105.
U203 19A705927P1 Silicon, bipolar: sim to Avantek MSA-0611.
U301 19A704971P9 Positive Voltage Regulator, 5 volt; sim to MC78L05ACD.
U302 19A116297P7 Linear: Dual Op Amp; sim to MC4558CD.
U303 19A704971P7 Voltage Regulator, Negative: sim to Motorola
MC79L05ACD.
U401 19A149944P201 Dual Modulus Prescaler: sim to Motorola
MC12022A.
U402 19B800902P5 Synthesizer, custom: CMOS, serial input.
U501 344A3070P1 Dual Operational Amplifier: sim to Motorola TL072.
U502 19A702705P4 Digital: Quad Analog Switch/Multiplexer.
U601 19A116297P7 Linear: Dual Op Amp; sim to MC4558CD.
U701 19A703483P302 Digital: Quad 2-Input NAND Gate;sim to 74HC00.
U702 19A703471P320 Digital: 3-Line To 8-Line Decoder;sim to
74HC138.
U705 19A703483P302 Digital: Quad 2-Input NAND Gate;sim to 74HC00.
- - - - - - - - VOLTAGE REGULATORS - - - - - - -
VR601 19B235029P7 5 Turn Cermet Trimmer: 5K ohms, + or - 10%, .5w,
and sim to 3296W-1502-R.
VR602
LBI-38671H
5

PRODUCTION CHANGES & IC DATA
U301
19A704971P9
+5V Regulator
U302 & U601
19A116297P7
Dual Wide Band Op-Amp
U202
344A3907P1
Silicon Bipolar MMIC
U303
19A704971P7
-5V regulator
U501
344A3070P1
Operational Amplifier
PRODUCTION CHANGES
Changes in the equipment to improve 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 descriptions of parts affected by these revisions.
REV. A - TRANSMITTER SYNTHESIZER BOARD 19D902779G3,6,7
To correct loading problem on synth IC which could cause failure to lock
on channel.
R707 was 47k ohms (19B800607P473).
REV. B - TRANSMITTER SYNTHESIZER BOARD 19D902779G3, G6-G7
REV. A - TRANSMITTER SYNTHESIZER BOARD 19D902779G8
To make new band splits compatible with helical filters. New PWB.
C15 was 0.1 µF (19A700004P2).
C16 was 330 pF (19A702061P73).
REV. A - TRANSMITTER SYNTHESIZER BOARD 19D902779G9
REV. B - TRANSMITTER SYNTHESIZER BOARD 19D902779G8
REV. C - TRANSMITTER SYNTHESIZER BOARD 19D902779G3, G6, G7
To meet hum & noise performance.
R101 was 47K ohm (19B800607P473).
C16 was 1500 pF (19A702061P89).
R9 was 680 ohm (19B800607P681) for G9.
R211 was 15 ohm (19B800607P150) for G9.
R214 was 15 ohm (19B800607P150) for G9.
R507 was 27K ohm (19B800607P150) for G9.
C5 was 3.9 pF (19A702236P15) for G9.
C6 was 18 pF (19A702236P32) for G9.
PWB was R1 return to R0.
REV. D - TRANSMITTER SYNTHESIZER BOARD 19D902779G3
To improve performance, C5 was 3.3 pF (19A702236P13).
REV. D - TRANSMITTER SYNTHESIZER BOARD 19D902779G6
To improve VCO tuning range, R9 was 680 ohms (19B800607P681).
REV. C - TRANSMITTER SYNTHESIZER BOARD 19D902779G8
To improve output level a wire was soldered between pins 3 and 4 and
between pins 9, 10 and 17 of FL101.
REV. A - TRANSMITTER SYNTHESIZER BOARD 19D902779G10
Adjust tuning range, C4 changed from 4.7 pF (19A702236P17) to 2.7
pF (19A702236P11).
U201 and U203
19A705927P11
Silicon Bipolar MMIC
LBI-38671H
6

IC DATA
U401
19A149944P201
Dual Modulus Prescaler
U402
19B800902P5
Synthesizer
U502
19A702705P4
Quad Analog Switch
U701 & U705
19A703483P302
Quad 2-Input NAND Gate
U702
19A703471P120
Address Decoder
LBI-38671H
7

OUTLINE DIAGRAM
UHF TRANSMITTER
SYNTHESIZER BOARD
19D902779G3, G6 - G10
SOLDER SIDE
COMPONENT SIDE
(19D902779, Sh. 2, Rev. 9)
(19D903361, Layer 1 & 4, Rev. 0)
LBI-38671H
8

SCHEMATIC DIAGRAM
UHF TRANSMITTER SYNTHESIZER
19D902780G3, G6 - G10
(19D903363, Sh. 1, Rev. 10)
LBI-38671H
9