11
pared to a reference voltage set during power-set proce-
dures. The dc feed voltage is corrected and supplied to
the controlled stages in the power amplifier module. A
pass device for the control voltage is located in the
power amplifier compartment.
C. Circuit Protection
Current- and temperature-sensing circuitry on the
power amplifier board feeds sensed voltages to the
command board for comparison. If the command board
suspects a fault condition, it overrides the power control
function and cuts the power back to a level that is safe
for the conditions.
D. DC
Interconnect
The ribbon cable connector carries sensed voltages
for power and protection to the command board. It also
carries A+ feed to the command board for distribution
throughout the internal transceiver housing, and it car-
ries control voltage from the command board to the
power amplifier board.
The rear battery connector (J1) carries A+ and A-
from the battery to the power amplifier board. The red
lead goes directly to the A+ terminal on the PA board.
The black A- lead from the battery connector ties to the
chassis, and connection to the power amplifier board is
made through the board mounting screws.
A- for the internal transceiver housing is through the
RF coax ground connectors, and through the mechani-
cal connection of the power amplifier heatsink to the rest
of the radio. During test conditions in which the power
amplifier assembly (board and heatsink) are physically
disconnected from the rest of the radio, it is acceptable
to rely on the coax cable connections to carry A- to the
internal housing.
VF VOLTAGE
SOURCE U5
VACUUM
FLUORESCENT
11-CHARACTER
U102
HIGH VOLTAGE
VF DRIVER
U101
MICROPROCESSOR
U1
EEPROM
U2
P5
J1001
P1001
MAEPF-21458-A
SERIAL BUS
INTERFACE
U4
MICROPHONE
VIP-IN/OUT
F3, 3A
F2, 3A
J4
P4
BATT CABLE (GRN)
IGN. CABLE (ORG)
SPEAKER
Spectra 9000 Control Unit
Figure 2. Functional Block Diagram for Spectra 9000 Control Head
MAEPF-21458-A
Содержание Spectra
Страница 6: ...v PERFORMANCE SPECIFICATIONS FOR SPECTRA PRIVACY PLUS TRUNKED CONVENTIONAL 900 MHz RADIO ...
Страница 7: ...vi PERFORMANCE SPECIFICATIONS FOR SPECTRA SMARTNET TRUNKED CONVENTIONAL 900 MHz RADIO ...
Страница 8: ...vii PERFORMANCE SPECIFICATIONS FOR SPECTRA 9000 RADIOS 900 MHz 30 WATTS ...
Страница 25: ...1 GENERAL INFORMATION 1 ...
Страница 73: ...53 INSERT GPW 7221 B Figure 22 Front Panel Diagnostics Key Closure Displays ...
Страница 75: ...INSERT GXW 4278 O PICKUP FROM PW 4320 O 55 CONTROL STATION WIRING DIAGRAM ...
Страница 79: ...PUSHBUTTON SPECTRA 900 MHz RADIO MECHANICAL EXPLODED VIEW 59 INSERT GXW 6225 B ...
Страница 96: ...82 MECHANICAL EXPLODED VIEW PARTS LIST FOR SPECTRA 900 MHz RADIO ...