10-Hz Oscillator

TM 32-5811-024-14&P

The test circuit consisting of U6A, U14A, and U12, functions as an AND gate that responds to high (i.e., 1) 1A, 1B,

1C, 1D, 2A, and 2B shift register bits by providing a high output. The PR code determines that all of these shift register

output bits will be 1 once every 63 clock pulse intervals, consequently their test output pulse will verify the correct

operation of the PR code generator in the 63-bit PR code mode.

CCA A10 may be externally wired to provide a 511-bit or 2047-bit PR code generator capability. The circuits used

for these operations perform in a similar manner as the 63-bit PR code generating circuits.

c. 10-Hz Oscillator. Stable multivibrator U4 provides a TTL 10-Hz output, which is applied to drivers U18 and U20.

These drivers are biased to provide a 10-Hz output that varies between +4 V and +5 V. This output is applied to the

communication processor transceiver I/O ECA to test its data link transceiver AGC threshold detect circuits.

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