Functional Description, Voltage Regulator Monitor Panel

TM 11-5895-1123-34

g. Upon receipt of the data at the input channels,

voice, or TTY signals which are then sent out to the

users.

the multiplexer combines all the data on the input

channels into one stream which is called the mission bit

stream.

2-7.

Functional Description, Voltage Regulator

h. This bit stream is routed through the data patch

Monitor Panel

panel to the KG-81 where it is encrypted.

The voltage regulator monitor panel at the bottom of

Encryption of the mission bit stream causes the terminal

rack 5 serves to monitor the output of the voltage

to appear to be operating at maximum traffic density at

regulator mounted behind the data patch panel at

all times, so that any change in the level of message

location A8 in rack 6. The regulated voltage is nomi nally

traffic cannot be detected.

115V vac. If the regulated voltage should fall outside

i. After being encrypted, the mission bit stream is

the limits set by the two red marker needles on the VR

patched through the Data Patch Panel to the online

monitor (meter-relay), contacts within the VR monitor

modem. In the modem, the pulse coded modulation

will close, illuminating the yellow VR fault lamp. The

(PCM) mission bit stream is applied to a 70-MHz IF

lower and upper voltage limits should normally be set to

carrier in the form of either biphase or quadraphase,

110 and 120 volts, respectively. The fault reset switch is

phase-shift keying (BPSK or QPSK).

used to clear a fault indication by the VR fault lamp after

j. In the coded mode of operation, the mission bit

the regulated voltage has been restored to a value

stream passes from the modem to the KY-801A/ GSC

within the preset limits. Momentary actuation of the

encoder-decoder unit by way of dedicated cabling. The

switch removes 24 vdc from the latching coils in the

coded mission bit stream then reenters the modem

meter-relay unit, allowing the contact to return to the

where it is PSK modulated onto the 70-MHz carrier.

open condition, which in turn removes power from the

k. Coding serves the purpose of significantly re

fault lamp A receptacle wired to the regulated 115 vac is

ducing the received energy-per-bit to noise ratio, Eb/ No,

pro vided on the VR monitor panel for the purpose of

required to achieve a given bit error rate (BER). In the

supplying power to the HP 436A power meter.

coded mode, a BER of 10-5 can be achieved with 5 dB

This power meter is part of the shelter test equipment.

less signal strength than that needed for the uncoded

mode. This improvement is accomplished by the

coder's ability to detect and correct errors arising from

noise in the received signal.

l. When receiving a BPSK or QPSK modulated,

70-MHz IF signal from the RSS, the opposites of the

processes described above are performed in reverse

order and direction through the CSS to result in digital,

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