PRODUCTION CHANGES
SYMBOL
PART NO.
DESCRIPTION
U303
19A704971P7
Voltage Regulator, Negative: sim to Motorola
MC79L05ACD.
U401
19A149944P201
Dual Modulus Prescaler: sim to Motorola
MC12022A.
U402
19B800902P7
Synthesizer , custom: CMOS, serial input
(Replaced 19B800902P5).
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
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
µ
F (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).
REV. E - TRANSMITTER SYNTHESIZER BOARD 19D902779G3 & G6
REV. D - TRANSMITTER SYNTHESIZER BOARD 19D902779G7 & G8
REV. B - TRANSMITTER SYNTHESIZER BOARD 19D902779G9 & G10
To accommodate new SOG synthesizer IC package U402 (PLCC
package discontinued). Modified printed wire board layout (Printed
wire board changed from 19D903361P1R0 to 19D903361P1R3).
Changed U402. U402 was a 19B800902P5. Installed RC compensa-
tion network resistor R313 and capacitor C314 in 8-volt regulator
circuit.
To make trimmer C10 adjustable to the required voltage level, 2.5
±
0.05 V. Changed capacitor C4 (19A702236P8) of Schematic Diagram,
Sheet 1 "Table of Values" under column G3 From 1.5pF to 2.2 pF
(19A702236P10).
REV. F - TRANSMITTER SYNTHESIZER BOARD 19D902779G3
To improve synthesizer power output at the high end of the band by
increasing the upper roll off point of the band pass filter. Changed
capacitor C209 in "Table of Values" under G3 from 2.2 pF to 1.8 pF.
Changed Resistors R211 and R214 in the "Table of Values" from 15
to 12. Deleted from the following designators the value only and added
an asterisk to C208, C210, R210, R212, R213 & R215. Added C208,
C210, R212, R213 & R215 to the "Table of Values".
REV. C - TRANSMITTER SYNTHESIZER BOARD 19D902779G10
To improve ability to set high and low frequency modulation pots
(VR601 & VR602). Also, to improve marginal output power at the high
end of the band. Changed capacitor C209 and inductor L204. Capaci-
tor C209, for G10, was 19A702236P8 (1.5 pF). Inductor L204 was
19A705470P10 (56 nH).
REV. A - TRANSMITTER SYNTHESIZER MODULE 19D902780G3, G6
THRU G10
To install RF shielding grommets. Installed item 9 RF shielding grom-
mets (19B802690P1) on two BNC connectors of input/output RF ports.
REV. B - TRANSMITTER SYNTHESIZER MODULE 19D902780G3, G6
THRU G10
To install a cover that has a conductive gasket. Changed item 3. Item
3 was 19D902509P2.
REV. G - TRANSMITTER SYNTHESIZER BOARD 19D902779G3
REV. F - TRANSMITTER SYNTHESIZER BOARD 19D902779G6
REV. E - TRANSMITTER SYNTHESIZER BOARD 19D902779G7
REV. E - TRANSMITTER SYNTHESIZER BOARD 19D902779G8
REV. C - TRANSMITTER SYNTHESIZER BOARD 19D902779G9
REV. D - TRANSMITTER SYNTHESIZER BOARD 19D902779G10
To increase the base current of transistor Q101 and ensure saturation
during turn on. Changed resistor R101. Resistor R101 was
19B800607P103, 10K Ohms.
REV. F - TRANSMITTER SYNTHESIZER BOARD 19D902779G7
To set 2.0 VDC on the VCO per Test Specification. Deleted capacitor
C4. Capacitor C4 was 1.5 pF, 19A702236P8. Changed capacitor C5.
Capacitor C5 was 3.9pF 19A702236P15.
REV. F - TRANSMITTER SYNTHESIZER BOARD 19D902779G8
To enable the VCO voltage to be adjusted properly, with variable
capacitor C10 set near the center of its adjustment range. Changed
inductor L1 and capacitors C4 and C6. Inductor L1 was 1-1/2 turn RF
coil 19C85100P3. Capacitor C4 was 0.5pF 19A702236Pl. Capacitor
C6 was 12 pF, 19A702236P28.
REV. H - TRANSMITTER SYNTHESIZER BOARD 19D902779G3
To improve synthesizer ability to lock consistently and reliably onto the
correct frequency by changing the inductors. Inductor L2 was
19A705470P24 (0.82 uH).
REV. 3A - TRANSMITTER SYNTHESIZER MODULE 19D902780G3,
G6-G10
To reduce RF emissions, the conductive connector grommet was
replaced with a thicker part to ensure contact with front panel at RF
connectors. RF Shielding grommet was 19B802690.
REV. 9A - TRANSMITTER SYNTHESIZER BOARD 19D902779G3
REV. 7A - TRANSMITTER SYNTHESIZER BOARD 19D902779G6-G8
REV. 4A - TRANSMITTER SYNTHESIZER BOARD 19D902779G9
REV. 5A - TRANSMITTER SYNTHESIZER BOARD 19D902779G10
To reduce RF emissions, the conductive gasket AG102834V1 on
solder side of board to close slot between board and chassis adjacent
to backplane connector.
LBI-38671N
6
