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Chameleon Knowledge Base · The Complete Online HF Antenna Handbook

MPAS 2.0 NVIS Configuration

For deliberate regional/NVIS work, use the 73 ft wire low and horizontal between two supports, with the feed and far end at roughly the same 10–12 ft guide height.

MPAS READY Handbook 02 Configurations Reviewed 2026-07-14
In plain language: For deliberate regional/NVIS work, use the 73 ft wire low and horizontal between two supports, with the feed and far end at roughly the same 10–12 ft guide height.

The Horizontal NVIS configuration exists for the path a vertical often misses: dependable regional coverage on lower HF when conditions support near-vertical incidence.

Build the documented shape

  • Use the 73 ft antenna wire as the horizontal radiator.
  • Place the HYBRID end and far end about 73 ft apart and 10–12 ft high.
  • Run the 25 ft counterpoise down from the matching unit and along the ground beneath the wire as shown.
  • Use nonconductive support line and proper strain relief.

Why an operator chooses it

The low horizontal geometry intentionally favors high-angle radiation on lower HF. It is also predominantly omnidirectional, which suits a regional net with stations in several directions.

Read the site before opening the bag

A beach, desert, or snow surface can change the useful starting height; the guide notes that lower heights may be necessary in those conditions. Record the actual height and result.

Common ways this goes wrong

  • Calling any low wire “NVIS” without checking band and propagation.
  • Making the wire tight enough to load the connectors.
  • Omitting the counterpoise.
  • Letting the feed line or nearby metal redefine the installation.

Before you transmit

  • Confirm the exact radiator, matching unit, return path, feed line, and support arrangement.
  • Keep conductors and supports clear of power lines and uncontrolled public access.
  • Reproduce the guide dimensions before experimenting.
  • Inspect every connection and begin testing at low power.
  • Record geometry, band, tuner state, and the result before changing one variable.
Boundary: NVIS is propagation-dependent. The configuration supports the objective; it does not guarantee range or a link.
Use the current source before deployment.

This lesson explains the decision. The official guide controls assembly, ratings, configuration details, and safety.

Open the MPAS 2.0 User Guide · Open the MPAS READY Product Guide · View the current product page

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