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Reviews Categories | Antennas: HF: Vertical, Wire, Loop | CHA M-LOOP Help


Reviews Summary for CHA M-LOOP
CHA M-LOOP Reviews: 2 Average rating: 5.0/5 MSRP: $675
Description: 3.5-54 MHz

The CHA M-LOOP is a 36" wide capacitively coupled magnetic
loop antenna made of a single piece of 1" diameter aluminum
tubing. This antenna is small, operates well when mounted at
ground level, and exhibits performance that competes with
almost any HF antenna except a multi-element beam at a
wavelength or more above ground.

The coupling of the antenna is achieved with multiple variable
capacitors and use a capacitive voltage divider technique
developed for the Patterson Loop (Army-Loop) in 1960’s. In
other word, no Faraday coupling loop is needed to play with in
order to bring the M-LOOP to great resonance.

Because of its unique coupling technique the M-LOOP will
tune easily even at very close proximity of metallic or
electrically conductive surfaces. Successful antenna tuning
attempts (providing very efficient radiation and transmissions
results) have been realized with the M-LOOP placed directly on
an industrial metal working bench or on an open pick-up
vehicle back door. The same great results have been obtained
while operated on a widely popular urethane coated metal
pick-nick park table.

Also due to the same great coupling technique the M-LOOP
can be used with various length of wire to cover 160M.

Compared with other magnetic loop antennas on the market
that are made of coax cables and that have tendency to sag,
the M-LOOP is made of a 1” diameter circular aluminum
tubing. The loop is firmly attached to the suitcase by custom
aluminum connectors that allow the loop to rotate freely at
360º around it.

The M-LOOP is free-standing and doesn’t require any support
to be operated. It is now easier than ever to rotate the antenna
to seek strong signals without the fear of having to retune it.

One of main problem with magnetic loop antennas is that they
are not very easy to transport in the field. They’re usually made
of a flimsy and rather poorly designed plastic cover that
protects the tuning capacitor. Chameleon Antenna has solved
that problem! The matching box has been designed to fit into
an ultra high-strength polypropylene copolymer resin that is
UV, solvent, corrosion and fungus resistant. The top lid is
equipped with a complete gasket seal making the case
absolutely water resistant.

The M-LOOP can be installed on a regular tripod (1/4” or 3/8”
threads) with the help of an aluminum plate that has been
attached under the case. The aluminum plate also provides a
counter-weight that balances nicely the antenna when used on
a flat surface.

Because multiple variable capacitors are either used in series
or parallels, the minimum capacitor voltage rating has been
increased beyond QRP limits.

The antenna is ideal for restricted operating areas and for
portable operation. The M-LOOP can work close to the
performance of a full size dipole antenna (sometimes
exceeding a dipole) and do not require radials. The antenna
can be mounted low to the ground, and will exhibit a high level
of performance.

Specifications:
Frequency: 6M – 80M
Power: 35W CW or 70W SSB (Might vary with the air humidity
percentage)
RF Connection: SO-239
Length: 36" Diameter
Weight: 8.5 lb.

The antenna system consists of:

1 X CHA M-LOOP Matching Box
1 X 36" LOOP
1 x 12' RG58A + Integrated RFI Choke
Product is in production.
More info: http://chameleonantenna.com/
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KF7IWZ Rating: 5/5 Apr 25, 2015 10:34 Send this review to a friend
Chameleon Antenna does it again  Time owned: 0 to 3 months
I wanted a solution that did not require towers, long wires, or multiple ground radials. Something that could reduce the amount of equipment I would need to transport and set up. And something that could do all of that from 6 to 80 meters. Well for my requirements this thing hits the mark and I haven't found anything else that can. Tunes up easily on all of the bands it should and just works. Yes, I could build my own...not what I'm into and it would cost me a fortune to build at this level of quality. Yes there are cheaper loops.....I wanted the 6-80 coverage and a loop that I can break down for transport or replace as my needs and options do, yes I understand the limitations. Is it the perfect solution to everything amateur radio.....no but it is the perfect solution for my needs. The manufacturer publishes all of the relevant information to help you decide if it is the right antenna for you and is quick to respond to your questions if you need more information. Bottom line, I can throw this thing on the kitchen table, on the hood of my truck, on top of my cooler, I don't need more towers or trees or ropes. This thing has changed my perspective and instead of looking for an antenna to maximize my radio I'm now looking for another radio to maximize my antenna.
 
K0FTC Rating: 5/5 Dec 7, 2014 06:44 Send this review to a friend
Quality Antenna  Time owned: 0 to 3 months
The Chameleon Mag Loop is a capacitive coupled (vs. inductively coupled) magnetic loop for 6 to 80 meters. It uses a 36" aluminum loop, 3 capacitor on/off switches (a variety of combinations of on/off is used for each band), a tuning knob and a matching knob. This antenna does not require height to operate well. It would work well for those with antenna restrictions or limited space/ability to use other antennas, portable in the field , and amateurs traveling via vehicle for business/leisure from campgrounds or motels. It is easy to set up, free standing or on a tripod.

This is a quality piece of equipment. It is well made and durable. It does not have the characteristic induction loop like many of the other mag loops on the market today. Machining on the parts is second to none, it has a black anodized face plate, and the fit and finish is wonderful. The loop can be oriented in any direction from the control box and can be rotated about its axis to fit unique circumstances. The control box it self is heavy duty, as well as the aluminum plate on the bottom for attaching to a tripod.

This antenna should not be used with an antenna tuner. The antenna itself must be tuned to as close to 1:1 resonance as possible by using the tuning and matching knobs for it to work. Its very easy to tune, just turn on/off the right combination of switches for the band you want, tune your radio to the desired frequency, use the tuning knob until the background noise is the highest and then use the matching knob to bring it to resonance. I would recommend fine tuning with any device that can indicate what the SWR is. I've used the WM-2 SWR meter (tuning for least reflected power), a N7VE's Tayloe SWR Indicator/Bridge kit (from Hendricks/QRP), and a K6VHF Magic Bridge (modified with a "operate/tune" switch installed by N0TA). They all work well for this part of the tuning process. The last two SWR devices have the advantage of allowing you to tune your radio without risk to your finals when using them in tune mode. These are QRP devices, and I use them with an FT-817 for QRP operation, but also have them between the radio and an Tokyo HY-Power HL-45B amplifier when I want a bit more power (tune the antenna with the amp off). This antenna does handle more power then QRP, but caution should be used when above QRP as far as distance from the antenna because of the RF exposure risk. When I use more then 5 watts, I tune the antenna at the radio and then move it about 10 or 12 feet away from the operating position, and still don't use more then 30-35 watts. I am strictly an CW op, but there are others using this antenna successfully on SSB.

This antenna works very well for what it is designed to do. I can operate inside the house with ease, as it does not require being more then about 3' or so above the ground to work well. So I've operated it from the kitchen table and the coffee table in the living room. The model I have has a one piece loop, so a 36" loop could be carried in the field, but not as easily as the new loop that is being offered that comes in 3 pieces. Chameleon makes good products and I've bought and used several of the antennas and masts they offer. Everything I've bought from Chameleon is well designed and rugged as I do quite a bit (for me) of field type work, especially from the vehicle and using a generator for power. I've not had the antenna long enough to have given it a field test, but I don't doubt that it will perform even better when I do get out.

I think expectations as to performance should be realistic - its not a Yagi on a mast pushing 1500 watts - but you can get good results and many report results similar to a dipole. Plus, you can take it with you wherever you go - much harder to do that with a Yagi on a tower -HI. I've had very good results working mostly QRP, but, as always when working low power, conditions are critical, and its the other person's ability to copy your signal that are important to your success. It can handle increased power above QRP, unlike many of the hand tuned loops on the market.

For more information: http://chameleonantenna.com/PORTABLE%20ANTENNA/CHA%20M-LOOP/Chameleon%20M-LOOP.html

I've got no personal relationship/interest in Chameleon. Just a satisfied customer. 73, John K0FTC
 


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