What Is the CHA LEFS 4010?
The CHA LEFS 4010 is a lightweight, portable end-fed half-wave (EFHW) antenna system designed for rapid operation on the 40, 20, 15, and 10-meter amateur bands without an antenna tuner under normal installation conditions. Its approximately 65-foot radiator, 49:1 matching transformer, integrated line winder, and compact End Assembly make it especially practical for POTA, SOTA, hiking, camping, emergency communication, and space-conscious home installations.
The system is more than a single end-fed wire. The End Assembly contains separate connections for the standard EFHW radiator and for officially supported optional dipole wire sets. This allows one compact feed and storage platform to support several distinct antenna configurations without confusing their electrical behavior.
Why Does It Exist?
Portable operators often face a three-way compromise between antenna efficiency, operating convenience, and equipment weight. Broadband antennas may require a tuner and can sacrifice efficiency. Fully resonant dipoles perform well but may require band links, multiple wire sets, or additional supports. The CHA LEFS 4010 was designed as a practical middle ground: a resonant multiband wire antenna that covers four heavily used bands without routine adjustment while remaining light enough for a backpack.
How the Standard EFHW System Works
A half-wave radiator fed near one end presents a high feed-point impedance. The CHA LEFS 4010 uses a 49:1 impedance transformer to transform that impedance toward the range expected by a 50-ohm transceiver system. Because the approximately 65-foot radiator supports related standing-wave modes, it can operate on 40, 20, 15, and 10 meters without changing the wire length.
Installation still matters. Feed-point height, radiator slope, nearby objects, soil, support materials, and feed-line routing can shift resonance and change the radiation pattern. The matching transformer does not make the antenna independent of its surroundings.
Supported Bands
| Operating method | Supported bands | Operator action |
|---|---|---|
| Standard 65-foot EFHW | 40, 20, 15, and 10 meters | No tuner normally required after a suitable installation is verified |
| Standard EFHW with a suitable tuner | 30, 17, and 12 meters in addition to the resonant bands | Use the tuner within its matching range and observe system losses and power limits |
| CHA LINK-D optional dipole | 40, 30, and 20 meters | Select the band using the dipole links |
| CHA LINK-D15 optional dipole | 40, 20, and 15 meters | Select the band using the dipole links |
| CHA WARC-D optional dipoles | 30, 17, and 12 meters | Install the appropriate single-band dipole wire set |
Two Feed Systems in One End Assembly
For normal LEFS 4010 operation, connect the 65-foot radiator to the terminal marked EFHW and connect the feed line to the BNC socket marked EFHW. Use the carabiner and suspension point for mechanical strain relief so the electrical terminal does not carry the wire tension.
For an optional supported dipole, connect both dipole legs to the terminals marked DIPOLE and move the feed line to the BNC socket marked DIPOLE. The dipole wiring and EFHW wiring are different antenna systems and must not be mixed.
Deployment Options
End-Fed Sloper
The sloper is the fastest standard deployment. Raise the End Assembly approximately 15 to 20 feet, extend the wire downward and away from the feed point, and secure the far end with light tension. This configuration requires only one elevated support and is well suited to portable operation.
Horizontal and NVIS-Oriented Deployment
With two supports, the EFHW radiator can be installed horizontally. The user guide documents approximately 12 to 15 feet at both ends for a 40-meter NVIS-oriented configuration. Lower horizontal installation tends to favor higher radiation angles and regional coverage, while greater height generally shifts more energy toward lower angles.
Optional Dipole Deployment
The CHA LINK-D, CHA LINK-D15, and CHA WARC-D wire sets may be installed as horizontal or inverted-V dipoles using the dedicated DIPOLE connections. An inverted-V description applies to these balanced dipole options, not to the standard single-wire EFHW radiator.
Power Limits
| Mode | Maximum power |
|---|---|
| SSB voice | 100 W |
| CW | 50 W |
| Digital and other high-duty-cycle modes | 25 W |
These limits are mode-specific. Do not assume that a 100-watt SSB rating permits 100 watts of FT8, RTTY, JS8Call, or another sustained-duty transmission.
Strengths
- Four popular bands without routine tuning or band switching.
- Approximately 1.0 to 1.1 pounds depending on the selected configuration and feed line.
- Fast one-support sloper deployment.
- Compact End Assembly with integrated storage and strain relief.
- Optional resonant dipole expansion for 40 through 12 meters.
- Useful for portable, emergency, stealth, and permanent installations.
Limitations
- The approximately 65-foot radiator requires meaningful deployment space.
- SWR and radiation behavior depend on the installation.
- The lightweight wire must not be pulled taut.
- 30, 17, and 12 meters require a suitable tuner in the standard EFHW configuration or an appropriate optional dipole.
- The published mode-specific power limits must be respected.
- A safe elevated support is required.
When Should You Use It?
Choose the CHA LEFS 4010 when you want a light and efficient multiband wire antenna, have at least one safe elevated support, can deploy approximately 65 feet of wire, and primarily operate on 40, 20, 15, or 10 meters. It is particularly strong for operators who prefer to leave the tuner at home during a portable activation.
When Should You Choose Something Else?
Choose another system when you lack a safe support, cannot deploy a 65-foot wire, require power above the published limits, or need immediate broadband access to many nonresonant frequencies. Operators needing a smaller physical footprint may prefer a compact loop, while operators wanting a highly configurable vertical system may prefer an MPAS READY solution.
Best Practices
- Keep all parts away from power lines and utility wires.
- Use the carabiner and suspension point for strain relief.
- Allow slight sag and never pull the radiator taut.
- Use the BNC socket that matches the selected EFHW or DIPOLE terminals.
- Route the feed line away from the radiator where practical.
- Use the integrated feed-line choke supplied with compatible Chameleon feed-line options.
- Verify SWR at low power after every materially different installation.
- Observe RF-exposure requirements and keep people away from the transmitting antenna.
Where Should I Learn Next?
- CHA LEFS 4010 Sloper Installation Guide
- CHA LEFS 4010 Horizontal and NVIS Deployment Guide
- CHA LEFS 4010 POTA Configuration Guide
- How a 49:1 Transformer Works
- CHA LINK-D System Overview
- CHA LINK-D15 System Overview
- CHA WARC-D System Overview
- CHA LEFS Series Troubleshooting and Maintenance
