CHA P-LOOP 2.0
Page 4
The proprietary design of the coupling loop is rigid and does not have solder joints. It is skillfully machined and
everything is held mechanically with a standard 3/8-24 large nut. The rigid coupling loop maintains its
symmetry, thus ensuring the same easy and efficient tuning. It also remains in the same plane as the radiating
loop, which maximizes radio frequency radiation and performance.
The CHA P-LOOP 2.0, see plate (1), is comprised of a 33¾ inch diameter flexible radiator loop, a rigid coupling loop,
a telescoping mast with handle and tripod mount, a specially designed tuning unit, and coaxial feed line
–
all of
which fit in the supplied Olive colored classic military-style messenger bag.
The CHA P-LOOP 2.0
doesn’
t require a ground-plane
and doesn’t need to be mounted up high. Do not use an
antenna tuner or coupler, as it may cause you to mistune the antenna.
Antennas built by Chameleon Antenna
TM
are versatile, dependable, stealthy, and built to last.
Please read this operator’s manual so that you may maximize the utility you obtain from your
CHA P-LOOP 2.0
antenna.
HF Propagation
HF radio provides relatively inexpensive and reliable local, regional, national, and international voice and data
communication capability. It is especially suitable for undeveloped areas where normal telecommunications are
not available, too costly or scarce, or where the commercial telecommunications infrastructure has been damaged
by a natural disaster or military conflict.
Although HF radio is a reasonably reliable method of communication, HF radio waves propagate through a
complex and constantly changing environment and are affected by weather, terrain, latitude, time of day, season,
and the 11-year solar cycle. A detailed explanation of the theory of HF radio wave propagation is beyond the
scope of this operator’s manual, but an understanding of the
basic principles will help the operator decide what
frequency will support their communication requirements.
HF radio waves propagate from the transmitting antenna to the receiving antenna using two methods: ground
waves and sky waves.
Ground waves are composed of direct waves and surface waves. Direct waves travel directly from the transmitting
antenna to the receiving antenna when they are within the radio line-of-sight. Typically, this distance is 8 to 14
miles for field stations. Surface waves follow the curvature of the Earth beyond the radio horizon.
They are usable, during the day and under optimal conditions, up to around 90 miles, see table (1). Low power,
horizontal antenna polarization, rugged or urban terrain, dense foliage, or dry soil conditions can reduce the range
very significantly. The U.S. Army found that in the dense jungles of Vietnam, the range for ground waves was
sometimes less than one mile.
Frequency Distance Frequency Distance
2 MHz
88 miles
14 MHz
33 miles
4 MHz
62 miles
18MHz
29 miles
7 MHz
47 miles
24 MHz
25 miles
10 MHz
39 miles
30 MHz
23 miles
Table 1. Maximum Surface Wave Range by Frequency.
