Chameleon Antenna CHA EMCOMM II V2 - User Manual

Revised November 7, 2020
Portable HF Antenna
(CHA EMCOMM II V2)
Operator’s Manual
Nevada - USA
WWW.CHAMELEONANTENNA.COM
VERSATILE – DEPENDABLE – STEALTH – BUILT TO LAST

Summary

Introduction

HF Propagation

Parts of the Antenna

Antenna Components

Identifies key parts including the Matching Transformer, Antenna Wire, Isolation Loops, Carabiner, and Wire Connector.

Transformer Connections and Storage

Details the Line Winder, UHF Socket, Top/Bottom Transformer Connections, and Transformer Eyebolt.

Antenna Configurations

Horizontal NVIS Configuration

Special configuration for good NVIS propagation on lower frequencies. Omnidirectional.

Sloping Wire Configuration

Broadband short to medium range HF antenna for ground and sky wave propagation.

Inverted L Configuration

Broadband antenna for short to medium range HF, favors horizontal end, good for ground waves.

Recovery Procedure

Troubleshooting

Specifications

Accessories

Recommended non-supplied accessories

References

Chameleon Antenna Products

Overview

1. Usage Features
2. Maintenance Features
3. Troubleshooting

The Chameleon Antenna™ Portable High Frequency (HF) Antenna (CHA EMCOMM II V2) is a versatile and dependable antenna system designed for both backup emergency HF systems and permanent installations. It is engineered to provide reliable local, regional, national, and international voice and data communication capabilities, particularly suitable for undeveloped areas or regions where telecommunications infrastructure may be damaged. The antenna's integral broadband impedance matching network transformer allows for wide-range antenna tuning, operating across a broad spectrum from 1.8 to 54 MHz, encompassing the 160m to 6m amateur bands, without requiring adjustments when used with a wide-range antenna tuner or coupler.

The CHA EMCOMM II V2 is a robust solution for various organizations, including military, government agencies, non-governmental organizations (NGOs), Military Affiliate Radio System (MARS), Civil Air Patrol (CAP), Amateur Radio Emergency Service (ARES) / Radio Amateur Civil Emergency Service (RACES), Salvation Army Team Emergency Radio Network (SATERN), and First Responders. Its design also makes it an ideal choice for amateur radio enthusiasts living in apartments, condominiums, or developments with homeowner's associations, deed restrictions, or CCRs (Covenants, Conditions & Restrictions), where stealth and minimal visual impact are often desired.

A key feature of the CHA EMCOMM II V2 is its configurability, allowing it to facilitate Near-Vertical Incident Skywave (NVIS) communication. This capability is crucial for filling the "skip zone" gap between ground wave and skywave propagation, enabling communication over short to medium distances (typically 40 to 300 miles) that are often difficult to cover with traditional HF skywave. The antenna is also totally waterproof, ensuring durability and reliability in various environmental conditions. While it does not strictly require a ground plane, its performance can be enhanced with one, for which a ground terminal is provided.

The antenna system comprises several components: a Matching Transformer, a 60-foot insulated Antenna Wire, Isolation Loops (circular insulators) permanently attached to the ends and middle of the Antenna Wire, a removable pear-shaped stainless steel Carabiner with a spring-loaded gate, and a Wire Connector at the end of the Antenna Wire for connection to the Matching Transformer. Other components include a Line Winder for storing the Antenna Wire, a UHF Socket (SO-239) on the Matching Transformer for coaxial cable connection, Top and Bottom Transformer Connections, and a Transformer Eyebolt for mounting.

The CHA EMCOMM II V2 can be deployed in multiple configurations, each offering unique performance characteristics. The manual describes three primary configurations: Horizontal NVIS, Sloping Wire, and Inverted "L."

The Horizontal NVIS configuration is specifically designed for good NVIS propagation on lower frequencies (typically below 10 MHz). It is predominantly omnidirectional and also provides medium-range skywave propagation on frequencies above 10 MHz. This setup requires two supports to raise the Matching Transformer and the end of the Antenna Wire to a height of 10-12 feet, with the supports approximately 60 feet apart. While higher or lower heights can be used, they may reduce NVIS performance. A counterpoise wire of 50-55 feet is recommended, or alternatively, a coaxial cable of 25-100 feet can serve as the counterpoise.

The Sloping Wire configuration is a broadband short-to-medium range HF antenna, providing acceptable ground wave and skywave propagation. It is primarily omnidirectional, becoming slightly bidirectional towards both ends as the frequency increases. This configuration requires one support, ideally mounted at a height of 25-40 feet for optimal performance. A counterpoise wire of 20-40 feet is recommended, or a coaxial cable of 25-100 feet can be used as the counterpoise. An alternative, the "Half Sloper," involves attaching the antenna to a metal tower and feeding it from the top.

The Inverted "L" configuration is another broadband short-to-medium range HF antenna. It tends to be unidirectional, favoring the horizontal end of the antenna. This setup is effective for ground wave communication during the daytime on frequencies between 1.8-4.0 MHz without relying on skywave propagation. It requires two supports, ideally mounted at a height of 25 feet for best performance, though good performance can still be achieved at 10-20 feet, and it is usable as low as three feet. A counterpoise wire of 20-40 feet is recommended, or a coaxial cable of 25-100 feet can serve as the counterpoise.

Usage Features:

The deployment process for each configuration involves site selection, connecting the Matching Transformer, raising the antenna, and extending the counterpoise (if used). For Horizontal NVIS:

1. Site Selection: Choose a site with two supports 60 feet apart, allowing the antenna to be 10-12 feet high.
2. Transformer Connection: Attach the Carabiner from the Antenna Wire to the Transformer Eyebolt, and the Wire Connector to the Top Transformer Connection. If using a counterpoise, connect it to the Bottom Transformer Connection. Connect the coaxial cable (with an RFI choke) to the UHF Socket.
3. Antenna Raising: Use paracord and a throw weight to loop over the supports. Raise the Matching Transformer end to 10-12 feet and secure it. Similarly, raise the end of the Antenna Wire to 10-12 feet, ensuring it is not taut, and secure it.
4. Counterpoise Extension: If using a counterpoise, extend it along the ground under the raised antenna portion.
5. Operational Test: Perform a test to ensure functionality.

For Sloping Wire:

1. Site Selection: Choose a site with one support to position the end of the Antenna Wire at 25-40 feet high.
2. Transformer Connection: Similar to NVIS, connect the Carabiner to the Transformer Eyebolt and the Wire Connector to the Top Transformer Connection. Connect the counterpoise (if used) to the Bottom Transformer Connection and the coaxial cable to the UHF Socket.
3. Antenna Raising: Tie a short paracord to the Carabiner and drive a stake into the ground near the radio set, securing the paracord from the Matching Transformer to the stake. Tie a long paracord to the Isolation Loop at the end of the Antenna Wire. Use a throw weight to loop the paracord over the support. Raise the end of the Antenna Wire to the desired height, ensuring it's not taut, and secure it.
4. Counterpoise Extension: Extend the counterpoise wire along the ground away from the antenna wire.
5. Operational Test: Perform a test to ensure functionality.

For Inverted "L":

1. Site Selection: Choose a site with two supports to position the corner of the "L" and the end of the Antenna Wire at 25 feet high.
2. Transformer Connection: Similar to other configurations, connect the Carabiner to the Transformer Eyebolt and the Wire Connector to the Top Transformer Connection. Connect the counterpoise (if used) to the Bottom Transformer Connection and the coaxial cable to the UHF Socket.
3. Antenna Raising: Tie a short paracord to the Carabiner and drive a stake into the ground near the radio set, securing the paracord from the Matching Transformer to the stake. Tie a long paracord to the Isolation Loop at the end of the Antenna Wire. Use a throw weight to loop the paracord over the support closest to the radio set. Pull the paracord and the end of the Antenna Wire over the support. Use another throw weight to loop the paracord over the other support. Pull the paracord to ensure the Antenna Wire is not taut, and secure it.
4. Counterpoise Extension: Extend the counterpoise wire along the ground under the antenna wire.
5. Operational Test: Perform a test to ensure functionality.

Maintenance Features:

The manual outlines a clear recovery procedure for disassembling and storing the CHA EMCOMM II V2:

1. Disconnect the Coaxial Cable from the radio set.
2. Lower the antenna to the ground.
3. Disconnect the Coaxial Cable from the Matching Transformer.
4. Carefully roll (without twisting) the Coaxial Cable.
5. Untie any paracord from the Matching Transformer and Antenna Wire.
6. Disconnect the Antenna Wire and counterpoise wire (if used) from the Matching Transformer.
7. Roll the Antenna Wire onto the Line Winder and secure it with the attached elastic cord.
8. Pull any stakes from the ground.
9. Remove dirt from antenna components and inspect them for signs of wear.
10. Store all components together.

Troubleshooting:

The manual provides a systematic troubleshooting guide to address common issues:

1. Wire Connector: Ensure it is securely connected.
2. Antenna Wire: Inspect for breakage or signs of strain.
3. UHF Plugs: Ensure they are securely tightened.
4. Coaxial Cable: Inspect for cuts in insulation or exposed shielding; replace if damaged.
5. SWR Check: If the antenna is not operational, connect a Standing Wave Ratio (SWR) Power Meter and check SWR.
6. High SWR (greater than 10:1): Check the antenna tuner or coupler using its manual or manufacturer's procedure. Also, check the Coaxial Patch Cable connecting the radio set to the antenna tuner or coupler.
7. Coaxial Cable Replacement: If still not operational, replace the Coaxial Cable assembly, as most antenna system problems are caused by coaxial cables and connectors.
8. Continuity Check: Connect a Multi-Meter to the Antenna Wire to check continuity; replace assemblies that do not pass.
9. Matching Transformer Replacement: If still not operational after all other checks, replace the Matching Transformer.

The CHA EMCOMM II V2 is designed for ease of use and durability, making it a reliable choice for critical communication needs.

Chameleon Antenna CHA EMCOMM II V2 Specifications