Wj-8718A/Corm Option; Mechanical Characteristics; Equipment Supplied - Watkins-Johnson Company WJ-8718A/MFP Instruction Supplement

WJ-8718A/MFP
1.1. 7
WJ-8718A/CORM
OPTION
GENERAL DESCRIPTiON
The CORM (Carrier-Operated Relay) Option extends the functional capability of
the MFP Option to allow a comparison between the input signal strength and a programmed
threshold level. The COR threshold is set by first entering a single digit threshold code on the
microprocessor front panel keypad, and then terminating the command by pressing the THRS
switch once. The single digit code (0 through 9) entered with the instruction represents a
corresponding signal strength level in dBm. Once the threshold has been established the relay
will turn on when an incoming signal strength, greater than the set level, is detected. Consult
the WJ-8718A/MFP Operator's Manual for the specific codes and their respective thr·eshold
levels.
If a CORM equipped receiver is also equipped with the WJ-8718A/232M or 488M
Option, the COR threshold can be controlled remotely. Four bits of threshold data can be
commanded and monitored, and a fifth bit (COR ON/OFF flag) can be monitored. Refer to the
WJ-8718/CORM Instruction Supplement for any additional information.
1.2 MECHANICAL CHARACTERISTICS
The front panel section of the MFP Option is an assembly formed by mounting the
Type 791202-5 Encoder Assembly (MFP-A2) and the Type 794310 Front Panel Switch Encode
Assembly (MFP-A1) on the rear of the microprocessor front panel. The completed assembly
replaces the standard WJ-8718A HF Receiver front panel and the following standard front panel
mounted boards: Manual Tuning Module (A7), Frequency Display (A8), BFa Switch (A9), and
Front Panel Control (AID).
The front panel is constructed of aluminum with a photo-etched bezel overlay.
Momentary-contact push buttons are mechanically arranged in functional blocks. Within each
functional block, selection of a new operating parameter automatically deactivates a previously
selected switch, preventing simultaneous activation of buttons with inverse functions. With the
exception of the power switch and general purpose keys, each front panel switch contains an
LED indicator which glows when the switch is activated.
Memory address, BFa frequency, and RF frequency are displayed by 7-segment
LEDs. Frequencies are selected via keypad or a front panel tuning wheel. In addition, ther.e are
three LED fault lights which glow red on various invalid conditions. The remaining standard
WJ-8718A front panel features include a signal strength/line audio level meter,a stereo phone
jack, and potentiometers for phone level and RF gain control.
The rear panel contains an adapter plate for the particular set of options installed
in the receiver. '
1.3 EQUIPMENT SUPPLIED
The MFP Option consists of the following circuit boards:
a) Type 794275-X Synthesizer Interface
b) Type 794308-2 IF Interface
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