26. R-442 CIPHER TEXT RECEIVE SIGNAL PATH, MONITORING CIRCUIT (KY-57 ON,
MODE SWITCH SET TO C).
a. Signal routing with KY-57 ON. The received cipher signal is applied
from the antenna through the CG-1773 to the R-442 RF connector. From the RF
connector the cipher signal is applied through the RF and IF assemblies,
where the cipher signal is demodulated. The signal is applied from the IF
assembly A4000 (X-MODE switch set to X-MODE), through the R-442 and MT-1898,
to the J-3514/U pin D. Within the J-3514/U the cipher signal is applied to
J3 pin P, through the CX-13061/U, to the KY-57 J3 pin A.
b. Squelch disabling.
In the KY-57, the cipher signal is sensed,
energizing K3.
K3B energizes, applying a ground to KY-57 J3 pin T.
The
ground is applied through the CX-13061/U to the J-3514/U J3 pin L. Within
the J-3514/U the ground is applied to K2, through the J-3514/U and MT-1898,
to the R-442 squelch disable circuit; disabling the squelch.
c. Decoding.
The cipher signal entering J3 pin A is applied to the
decoder (decoded) and to the audio jack pin B KY-57. The signal is applied
through the CX-13062/U, J-3514/U, and MT-1898 to the R-442 AF A-5000
section. Then the signal is applied to the system as it was discussed in
plain text (Figure 97. Issued as adjunctive material.).
(Trace these
circuits on your system diagram.)
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