CHA EMCOMM III Portable Performance, NVIS, and DX Planning

A broadband antenna does not have one universal radiation pattern. The useful pattern is produced by the exact wire shape, height, orientation, ground, and band.

The CHA EMCOMM III Portable gives a field station more wire and more deployment choices than the smaller EMCOMM II V2 while remaining a one-pound, one-operator system. Its 73 ft radiator, transformer, line winder, and suspension hardware are designed to move from a backpack to an operating site in under 15 minutes.

What matters for this decision

• Use the guide’s low horizontal geometry and preserve the named endpoint heights, feed-point position, and return path.
• High-angle radiation can support regional paths only when the operating frequency is below the current critical frequency.
• A good analyzer match does not prove that the ionosphere will support NVIS.
• Record band, time, geometry, orientation, height, and on-air reports so the result can be repeated.

Why operators choose this system

The operator can choose a sloping wire or inverted-L when there is time to use one or two supports, an end-fed inverted-V when one center support and a faster layout make more sense, or a horizontal NVIS arrangement when regional coverage is the priority.

Published operating reference

• Published continuous frequency range: 1.8–55 MHz.
• Published power: 50 W continuous duty and 100 W intermittent duty.
• Published wire length and weight: 73 ft and approximately 1 lb.
• Published setup: one trained operator in less than 15 minutes.

Make the next deployment repeatable

Record product revision, configuration, wire dimensions and bearings, endpoint heights, support hardware, return path, coax and choke condition, tuner state, analyzer reference plane, weather, and on-air reports.