Figure 1-15.-PP-6140/ACQ-5 power supply.
Audio-to-RF conversion is accomplished when the
carrier frequency is modulated by the audio input. The
modulated RF is amplified by the RF amp to the selected
power level of 400 or 1000 watts, depending on the
mode selected on the control box, and then coupled to
the antenna for transmission.
DATA LINK SYSTEM
Learning Objective: Recognize components
and operating principles of a data link system.
The data link system serves as a communications
link that allows computer-to-computer exchange of data
between participating units. Airborne platforms capable
of data link include Air Force AWACS, P-3 patrol
aircraft, and most carrier aircraft. Surface or subsurface
platforms equipped with Navy tactical data systems
(NTDS) may also receive and transmit information over
data link. The data transmitted is sent by the central
computer to a communications interface, which
reformats the data into serial digital data (standard
NTDS) transmission language. The serial data is then
encrypted and passed through a modulator/demodulator
to make it compatible with the P-3 radios. Either HF-1,
HF-2, or UHF-2 may be used to transmit and receive
In general, the data link system is designed
exclusively to transmit tactical symbology. This
symbology is available in the aircraft for display on the
TACCO display. An additional function is plain text.
This allows transmission for text information through
link net. This information is available only to certain
Figure 1-16.-C-7790/ACQ-5 control monitor panel.
airborne platforms (P-3, E-2) and shore-based anti-
submarine warfare operating centers (ASWOCs).
Control of the data link setup and monitoring of the
active link net is the responsibility of the NAV/COMM.
Once it is set up and operating, the only software
function available to the NAV/COMM is plain text
transmission and reception. The TACCO controls the
transmission of all tactical data from the aircraft.
DATA LINK SYSTEM COMPONENTS
The major components of the data link system are
discussed in the following text.
Data Terminal Set Converter-Control,
This component is a modulator/demodulator
(modem) that takes 26-bit serial digital data from the
data communications interface and converts it into audio