E.F. Johnson Viking VX Series, Руководство пользователя

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CIRCUIT DESCRIPTION
6-11
September 1994
Part No. 001-2008-300
Pin 8 RF DATA A
Data A (U105, pin 11) is the least significant bit
(LSB) in the 3 multiplex chips located on the RFIB.
This pin is a CMOS input from the Controller requir-
ing a logic high for activation.
Pin 9 RF DATA C
Data C (U105, pin 9) is the most significant bit
(MSB) in the 3 multiplex chips located on the RFIB.
This pin is a CMOS input from the Controller requir-
ing a logic high for activation.
Pin 10 RF MUX2 INH
The Multiplexer-2 Inhibit (U106, pin 6) is a
CMOS input from the Controller that inhibits (dis-
ables) the output from the RF 2 Multiplexer with a
logic high.
Pin 11 RF CLK
The clock will control the synthesizer chips and
power control circuit when loading. This pin is a TTL
input from the Controller.
Pin 12 HS CS RX
Not used at this time.
Pin 13 RF MUX1 INH
The Multiplexer-1 Inhibit (U105, pin 6) is a
CMOS input from the Controller that inhibits (dis-
ables) the output from the RF 1 Multiplexer with a
logic high.
Pin 14 V REF EX
The 3.5V DC TCXO reference voltage from the
Exciter to the TPI card.
Pins 15-18 UNUSED
Pin 19 RF MUX3 INH
The Multiplexer-3 Inhibit (U104, pin 6) is a
CMOS input from the Controller that inhibits (dis-
ables) the output from the RF 3 Multiplexer with a
logic high.
Pin 20 LPTT
The Logic Push-To-Talk is an open collector
from the Controller. It has a sink capability of 20 mA
and a maximum voltage rating of 18V. The transmit-
ter should produce power when this pin is a logic low.
Pin 21 SYN CS EX
The main Synthesizer Chip Select in the Exciter
that allows input of data to the specific synthesizer
chip when the line is pulled to logic low.
Pin 22 TX MOD
The audio from the TPI card in the Controller
processes a number of inputs to the Universal Station
to produce the signals on this pin. This signal goes
through the RFIB and then to the Exciter. A 707 mV
RMS sine wave (2V P-P) at 1 kHz produces 60% of
system deviation in the transmitter. The source
impedance is low and the input impedance is less than
10k ohms.
Pin 23 GROUND
A pin that carries ground current between the
RFIB and CBP board.
Pins 24-25 UNUSED
Pin 26 RF DATA B
The Data B (U105, pin 10) is the middle signifi-
cant bit in the three multiplex chips located on the
RFIB. This pin is a CMOS input from the Controller
requiring a logic high for activation.
Pin 27 A D LEVEL
21 lines (of the possible 24) of RF functions sam-
pled are multiplexed to the Controller through this pin
using three multiplex chips.
1. RF Forward Power Sense
2. RF Power Sense Device 1
3. RF Power Sense Device 2
4. RF Power Sense Device 3
5. RF Power Sense Device 4
6. RF Reflected Power Sense
7. PA Temperature