CHA F-LOOP
Page 3
Introduction
Thank you for purchasing and using the Chameleon Antenna
TM
High Frequency (HF) Faraday Loop Antenna (CHA F-
LOOP).
The unique craftsmanship of the CHA F-LOOP distinguishes itself from the competition. You are now part of
the magnetic loop HF antenna craze that is sweeping the amateur radio community. Easily deployable HF
magnetic loop antennas, also called small transmitting loops, have been routinely used for many years in
professional defense, military, diplomatic, and shipboard HF communication links, where robust and reliable
general coverage radio communication is deemed mandatory. These antennas have only recently become
commercially available for amateur radio. You will be amazed by the performance of this antenna.
The real
practical advantage of the small loop, compared to a short vertical whip tuned against earth or a full sized vertical
antenna, is the loop’s freedom from dependence on a ground plane and earth for achieving efficient operation;
this unique characteristic has profound significance for small restricted space antenna operation. In comparison,
the bottom of a vertically oriented the loop does not need to more than a loop diameter above ground making it
very easy to site in a restricted space location. There is no significant improvement in performance when a small
loop is raised to great heights; all that matters is the loop is substantially clear of objects in the immediate area
and towards the desired direction of radiation. Field trials of the CHA F-LOOP demonstrated that an inside
magnetic loop antenna was only around one to two S-units lower, on both transmit and receive, than an outside
full size quarter wave vertical antenna. Remarkable for an antenna that is only less than three foot in diameter
and covers 5.3 MHz to 29.7 MHz (60 – 10 meter ham bands)! The magnetic loop is different than typical antennas
because it emphasizes the magnetic part of the radio wave (H field) rather than the electric part (E field) of the
radio wave. It also has a high Q resonance of around 15 KHz on 60 meters, providing immunity from interference
outside the bandpass. The CHA F-LOOP Antenna was designed with weight, portability, versatility and cost in mind
and is ideal for RV/camping, hotels, apartments, condominiums, homeowners associations, deed restrictions and
CCRs (Covenants, Conditions & Restrictions), Shortwave Listening (SWL) and other places where it is not feasible
to erect a multi-band wire or vertical antenna.
The standard CHA F-LOOP, see plate (1), is
comprised of a three foot diameter flexible radiator
loop, a Faraday loop, a proprietary takedown
hardline feeder section that minimize SWR variation,
a specially designed tuning unit, and coaxial feedline
– all of which fit in the supplied Flat Dark Earth (FDE)
/ Coyote Brown military-style MOLLE bag. A high-
efficiency 1” collapsible aluminum tubing radiator
loop, which increases efficiency an average of 142%
over the standard flexible radiator loop, is available
as an option. The CHA F-LOOP 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 F-
LOOP antenna.
Plate 1. Complete CHA F-LOOP 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.