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Information Systems Technician Training Series, Module 4 - Communications Hardware | Next
Ultra High Frequency Systems |
Figure 1-3.—High-frequency receive system.
Figure l-3 shows atypical high-frequency receive
system. Refer to the figure as we follow the signal path
through the system.
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A transmitted high-frequency signal is received
by the antenna, which converts electromagnetic
energy to electrical energy.
The signal travels through a transmission line to
an antenna patch panel, where it can be
distributed to any of a number of receivers.
The receiver converts the RF signal into a
teleprinter or voice signal, depending upon what
is desired.
The output of the receiver is then sent to the
receiver transfer switchboard.
If a teleprinter signal was selected, the
teleprinter signal from the switchboard goes to
the AN/UCC-1 and then follows the same path
as we described in the low-frequency receive
section. Identical pieces of equipment are used,
and they perform the same functions.
If a voice signal was selected, the voice signal
from the receiver transfer switchboard is sent to
the radio set control. The output is then sent to a
handset. The voice signal can also be sent from
the switchboard to a remote speaker amplifier.
There, it can be placed on a speaker so that the
1-4
user can listen to the received signal without
holding onto the handset.
VERY-HIGH-FREQUENCY SYSTEMS
The very-high-frequency (VHF) band (30-300
MHz) is used for aeronautical radio navigation and
communications, radar, amateur radio, and mobile
communications (such as for boat crews and landing
parties). Figure 1-4 shows a basic block diagram of a
Figure 1-4.—Very-high-frequency transmit and receive
system.
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