CHA EMCOMM III Base Selection and Application Guide

The better purchase is the antenna that fits the operator’s recurring job. More wire or a wider frequency label is not automatically more useful.

The CHA EMCOMM III Base is the deliberate member of the EMCOMM family: a full 130 ft radiator and weather-resistant matching transformer for stations that can invest in support height, routing, and a repeatable base installation. It is intended to cover short, regional, and long-distance HF jobs without changing antennas for every band.

What matters for this decision

• Choose the shortest, lightest system that still supports the required bands and path.
• Count the actual supports and usable height at the site.
• Include coax, return conductors, line, stakes, tuner, weather protection, and recovery time in the comparison.
• Inverted-L: general-purpose short-to-medium range arrangement, typically around 35 ft high, useful on restricted lots.
• End-fed inverted-V: one tall support, medium-range lower-band and longer-path upper-band behavior; keep the included angle above 120 degrees when possible.
• Half square: two vertical 33 ft sections separated by approximately 64 ft, strongest broadly perpendicular to the plane on the 7–20 MHz region.
• End-fed sloper: the documented special case where an existing conductive metal tower or mast serves as the return path.

Why operators choose this system

Its 130 ft length can be shaped as an inverted-L, end-fed inverted-V, half square, or end-fed sloper. Those four layouts let the site decide whether the priority is compact suburban use, broad regional coverage, stronger 7–20 MHz directional behavior, or integration with an existing conductive tower or mast.

Published operating reference

• Published continuous frequency range: 3.5–30 MHz.
• Published power: 200 W SSB and 100 W other modes under intermittent commercial/amateur service.
• Published wire length and weight: 130 ft and approximately 2.2 lb.
• Published setup: one trained operator in less than 30 minutes after the site and supports are ready.

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.