1.8-54 MHz. The Chameleon EMCOMM II Antenna has been specially designed for backup emergency HF system or permanent installation. The integral broadband impedance matching network (transformer 5:1) allows broadband antenna tuning. It is the perfect backup antenna for apartments, condominiums, homeowners associations, deed restrictions and CCRs (Covenants, Conditions & Restrictions), ARES, RACES, MARS, EMCOMM, NVIS, First Responders and especially for Emergency Preparedness. The unit is totally waterproof. The antenna is 60’ long and covers 6M to 160M. An external tuner is required.
Specifications:
The antenna system consists of:
1 X CHA EMCOMM II matching box
1 X 60’ wire
The antenna will perform very well with a sloper or an “Inverted-Vee” configuration. For a NVIS configuration (40M / 80M) the antenna must be installed horizontally with the ground and elevated between 9″ and 12″ high.The EMCOMM II does not require a ground-plane but will perform better with one. A ground terminal is available for that purpose. Power capacity is 500 watts SSB or 250 watts CW. SO-239 input.
NVIS Installation:
The sloper is considered the most unusual antenna system and can be difficult to get to work properly. The sloper may exhibit some gain in one direction, but usually has omni direction pattern. There are two types of sloper, the full sloper, really a dipole mounted with one end higher than the other. The half-sloper (EMCOMM II) is fed at one end with a “ground system” or counter poise provided by either physical ground if fed at lower end of sloper. If the sloper is fed at the top, then other factors provide the “ground”. In most cases, a sloper mounted on a tower, then the tower and importantly, the beam mounted on top, act as the counterpoise.One successful version of the sloper (most folks call any kind of sloper simply a “sloper” regardless of its type) is one that is fed with coax. The antenna is fed from the top and installed on a tower with a beam on top. The center conductor of the coax feeds the sloper wire and the shield is carefully bonded to the tower structure. In addition the beam, rotor, and mast are electrically bonded to the tower (here a heavy braided strap connecting the mast to the tower is recommended). The theory is that the sloper is fed at the top and the high current point is high just under the beam, leading away from the tower.
The sloper has been reported to be hard to get to work in some cases. When it works, its performance when used with a tower and a beam is very good. Considering the cost of materials (assuming the tower is in place already) the sloper should be considered.
Price: $115.00 USD