U.S. Marine Corps Antenna Mcrp 6 22D Operating Instructions

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MCRP 6-22D
x Chapter 8.  Antenna Farms
Command Post8-1
Tactical8-1
Main8-2
Rear8-2
Location Selection Considerations8-2
Doctrinal Considerations8-2
Tactical Considerations8-3
Technical Considerations8-5
Siting VHF Antennas8-6
Transmitting Antenna Site8-9
Receiving Antenna Sites8-11
Antenna Farm Internal Arrangement8-12
Frequency Band8-12
Antenna Selection and Placement8-12
Requirements8-14
Polarization8-15
Power and Signal Lines8-16
Antenna Farm Layout...

Chapter 1
Radio Principles
ELECTROMAGNETIC RADIATION
Electromagnetic radiation includes radio waves, microwaves, infra-
red radiation, visible light, ultraviolet waves, X-rays, and gamma
rays. Together they make up the electromagnetic spectrum. They all
move at the speed of light (186,000 miles/300 million meters per
second). The only difference between them is their wavelength (the
distance a wave travels during one complete cycle [vibration]),
which is directly related to the amount of energy the waves...

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MCRP 6-22D
RADIO WAVES
Radio waves propagate (travel) much like surface water waves.
They travel near the Earth’s surface and also radiate skyward at var-
ious angles to the Earth’s surface. As the radio waves travel, their
energy spreads over an ever-increasing surface area. A typical radio
wave has two components, a crest (top portion) and a trough (bottom
portion). These components travel outward from the transmitter, one
after the other, at a consistent...

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1-3
and the lower the frequency. The shorter the cycle time, the shorter
the wavelength and the higher the frequency.
Frequency is measured and stated in hertz (Hz). A radio wave fre-
quency is very high. It is generally measured and stated in thousands
of hertz (kilohertz [kHz]), in millions of hertz (megahertz [MHz]),
or sometimes in billions of hertz (gigahertz [GHz]).  
Frequency Calculation
For practical purposes, the velocity of a radio wave is...

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MCRP 6-22D
HF is used primarily for long-range communications. An HF signal
is reflected by the outermost portion of the atmosphere, the iono-
sphere. VHF is used for short-range communications. To use VHF,
it is necessary to be able to visualize a direct line of sight (LOS)
between the transmitter and receiver. This limits UHF to distances
that are not much greater than the distance to the horizon, assuming
that there are no massive obstructions in the LOS....

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1-5
RADIO COMMUNICATION CIRCUIT
The radio equipment for communicating between two stations,
including the path the radio signal follows through the air, is a radio
link. A radio link consists of seven components:  transmitter, power
supply, transmission lines, transmitting antenna, propagation path,
receiving antenna, and receiver.
 Table 1-2. Ground SCRs.
Frequency 
BandMAGTF SCR 
Equipment UsedOperating 
Frequency 
RangeTypical
Application
HFAN/PRC-104...

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MCRP 6-22D
The transmitter generates a radio signal. The power supply provides
power for the operating voltage of the radio (battery or generator).
The transmission line delivers the signal from the transmitter to the
transmitting antenna. The transmitting antenna sends the radio
signal into space toward the receiving antenna. The path in space
that the radio signal follows as it goes to the receiving antenna is the
propagation path. The receiving antenna...

Antenna Handbook ______________________________ 
1-7TRANSMISSION
LINESTRANSMITTING 
     ANTENNAPROPAGATIONPATH    RECEIVING      ANTENNAPOWERSUPPLYTRANSMITTERRECEIVERFigure 1-3. Typical Radio Link. 

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MCRP 6-22D
PROPAGATION FUNDAMENTALS
Earth’s Atmosphere
Propagation usually takes place within the Earth’s atmosphere. The
atmosphere surrounding the Earth is divided into several layers,
each possessing unique characteristics. The first layer, starting at
the Earth’s surface and extending to a height of about 10 kilometers
(km), is the troposphere. In this layer, the air temperature decreases
with altitude at the rate of about 2.5°C every 300 meters. 
The second...

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Ground Wave Propagation. Radio communications using ground
wave propagation do not use or depend on waves refracted from the
ionosphere (sky waves). Ground wave propagation is affected by
the Earth’s electrical characteristics and by the amount of diffrac-
tion (bending) of the waves along the Earth’s curvature. The ground
wave’s strength at the receiver depends on the transmitter’s power
output and frequency, the Earth’s shape and conductivity along...