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Chameleon Knowledge Base · The Complete Online HF Antenna Handbook

CHA LEFS 4010 Sloper Installation and Operating Guide

Deploy the CHA LEFS 4010 as a sloper by raising the End Assembly approximately 15–20 feet, extending the 65-foot radiator downward and away from the feed point, and leaving slight sag so the lightweight wire carries no structural tension.

Product Installation Guides CHA LEFS 4010 Reviewed 2026-07-14
Quick Answer: Deploy the CHA LEFS 4010 as a sloper by raising the End Assembly approximately 15–20 feet, extending the 65-foot radiator downward and away from the feed point, and leaving slight sag so the lightweight wire carries no structural tension.

What Is the Sloper Configuration?

The sloper is the primary rapid-deployment configuration for the CHA LEFS 4010. The End Assembly and feed point are elevated while the approximately 65-foot end-fed half-wave radiator slopes toward a lower anchoring point. This arrangement requires only one elevated support and is especially useful when a second tree or mast is unavailable.

The standard sloper uses the single EFHW radiator. It is not an inverted-V dipole and does not use the separate DIPOLE terminals.

Why Use a Sloper?

  • Only one elevated support is required.
  • One operator can normally complete deployment in approximately ten minutes.
  • The complete antenna remains compact and light enough for backpack operation.
  • No coil adjustment, band links, or radiator changes are required for 40, 20, 15, and 10 meters.
  • The feed point can remain accessible enough for inspection while still being elevated.

What You Need

  • CHA LEFS 4010 End Assembly
  • Approximately 65-foot CHA LEFS 4010 EFHW radiator
  • Selected Chameleon feed line with integrated RFI choke
  • Approximately 25 feet of nonconductive support cord for the End Assembly
  • Approximately 5 feet of support cord for the far end
  • One elevated support such as a suitable tree or lightweight telescopic pole
  • Tent stake or another safe nonconductive anchoring point when needed
  • Throw bag or another safe line-placement method when using a tree

Site Selection

  1. Choose a location that permits the full radiator to extend without crossing roads, trails, campsites, or public access areas.
  2. Maintain safe clearance from power lines and utility wires in every possible direction of movement.
  3. Avoid placing the radiator against metal fences, vehicles, buildings, or other conductive objects.
  4. Select a support that can place the End Assembly approximately 15–20 feet above ground for a typical field installation.
  5. If only a lower support is available, the antenna may still operate, but SWR, efficiency, and radiation behavior can change.
Safety: Never throw a line, raise a pole, or install any part of the antenna where it could contact an electrical conductor. Account for wind, falling branches, support failure, and the full length of the feed line and support cord.

Prepare the End Assembly

  1. Attach the main support cord to the large suspension point at the top of the End Assembly using a secure knot.
  2. Unwind the 65-foot radiator carefully from the integrated line winder.
  3. Clip the radiator carabiner to the suspension point. This provides mechanical strain relief.
  4. Attach the radiator terminal lug to the wing-nut terminal marked EFHW. Tighten it finger-tight.
  5. Connect the feed line to the BNC socket marked EFHW.
Connection check: The EFHW radiator must use both the EFHW terminal and the EFHW BNC socket. The separate DIPOLE terminals and DIPOLE BNC socket are reserved for the optional CHA LINK-D, CHA LINK-D15, and CHA WARC-D dipole wire sets.

Raise the Feed Point

  1. Place the main support cord over the selected support using a safe method.
  2. Raise the End Assembly to approximately 15–20 feet.
  3. Secure the support cord so the End Assembly cannot slide or fall.
  4. Confirm that the feed line hangs freely and is not carrying the antenna's mechanical load.

Extend and Anchor the Radiator

  1. Walk the radiator away from the feed point in the selected direction.
  2. Attach a short support cord to the insulator loop at the far end.
  3. Place the anchoring point approximately three feet beyond the end of the fully extended radiator when practical.
  4. Secure the support cord while allowing visible, gentle sag in the antenna wire.
  5. Do not pull the radiator taut. The 20-gauge wire is strong for its weight but is not a structural guy line.

Feed-Line Routing

Route the feed line away from the radiator where practical and avoid laying long sections directly parallel to it. The optional Chameleon RG-316 and compatible RG-58 feed-line configurations include an integrated RFI choke. Additional common-mode suppression should only be added when a specific installation demonstrates a need.

Verify Before Transmitting

  1. Inspect the EFHW terminal, BNC connector, carabiner, support cord, and far-end anchor.
  2. Confirm that no person can touch or walk into the radiator while transmitting.
  3. Check SWR using low power.
  4. If SWR is unexpectedly high, inspect the installation and connections before using a tuner.
  5. Begin operation at reduced power and confirm normal system behavior.

Supported Bands

Configuration Bands Tuner
Standard 65-foot EFHW sloper 40, 20, 15, and 10 meters Normally not required
Standard EFHW sloper on WARC bands 30, 17, and 12 meters Suitable tuner required

Power Limits

Operating mode Maximum power
SSB voice 100 W
CW 50 W
Digital and other high-duty-cycle modes 25 W

How Orientation Affects Performance

A sloper does not produce the same radiation pattern on every band. The official guide notes modest broadside directivity on 40 meters and increasing radiation toward the wire ends on 20 meters and above. Feed-point height, slope angle, surrounding terrain, and nearby objects can alter this behavior significantly.

For portable work, prioritize a safe and clear installation before trying to aim the antenna precisely. If the site permits, changing the slope direction can be a useful field experiment, but signal variation may also come from propagation.

Common Mistakes

  • Connecting the feed line to the DIPOLE BNC socket.
  • Allowing the EFHW wing-nut terminal to carry the wire tension.
  • Pulling the radiator taut.
  • Forgetting that 15 meters is one of the standard no-tuner bands.
  • Operating digital modes above 25 watts.
  • Routing the radiator or support cord across a public path.
  • Attempting to tune around a damaged feed line or loose connector.
  • Installing too close to power lines or conductive structures.

Recovery and Storage

  1. Disconnect the feed line from the radio before lowering the antenna.
  2. Lower the End Assembly in a controlled manner.
  3. Disconnect and loosely coil the feed line without twisting it.
  4. Release the far-end support and inspect the radiator for abrasion or damage.
  5. Wrap the radiator around the integrated line winder without sharp bends.
  6. Remove dirt and moisture before placing the antenna in its pouch.

When to Use Another Configuration

Use the horizontal EFHW configuration when two supports are available or when you want an approximately 12–15-foot NVIS-oriented installation. Use an optional CHA LINK-D, CHA LINK-D15, or CHA WARC-D wire set when you specifically want a balanced horizontal or inverted-V dipole.

Learn Next

  • CHA LEFS 4010 Product DNA: Complete System Overview
  • CHA LEFS 4010 Horizontal and NVIS Installation Guide
  • CHA LEFS 4010 POTA Deployment Guide
  • What Is a 49:1 Unun?
  • CHA LEFS Series Troubleshooting and Maintenance