Viking 242-2009-632 Service Manual page 96

CIRCUIT DESCRIPTION
Pin 10 UNUSED
Pin 11 GROUND
Pin 11 carries ground current between the RFIB
and the Receiver board.
Pin 12 SYN CS RX
Pin 12 is the Receiver main synthesizer chip
select. This chip is the same part as used in the
Exciter. A low enables loading the Synthesizer.
Pin 13 RX INJ
This pin is the power sense for the Receiver
injection. It is a linear voltage source that is a func-
tion of the injection power. The voltage level will be
between 0V - 5V and be able to drive a 10k ohm load.
Pin 14 SYN LK RX
Pin 14 is the main synthesizer lock detector out-
put for the Receiver. The synthesizer is locked with a
TTL logic high state.
Pin 15 GROUND
Pin 15 carries ground current between the RFIB
and the Receiver board.
March 1999
Part No. 001-2009-600
Pin 16 HS CS RX
Pin 16 is the 900 MHz Receiver high stability
synthesizer chip select. This synthesizer is the same
circuit as used in the Exciter. A low enables loading
the high stability synthesizer loop.
Pin 17 GROUND
Pin 17 carries ground current between the RFIB
and the Receiver board.
Pin 18 RF CLK
The clock controls the Receiver synthesizers
when loading. The input source in the Controller is
TTL with the speed determined by the synthesizer
chip. There could be as many as four synthesizers and
a shift register.
Pin 19 HS LK RX
This is the high stability synthesizer lock detector
output for the 900 MHz Receiver. The synthesizer is
locked with a TTL logic high state.
Pin 20 RF DATA
Pin 20 is a data pin from the Controller which has
the dual role of loading the synthesizer chips and
adjusting the power control D/A lines for proper out-
put power. The data has TTL levels. Up to four syn-
thesizer chips and a shift register could be connected
to this pin.
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