HFLW-230

The HFLW-230 is a highly versatile, HF Broadband Long Wire Antenna designed for elite tactical and strategic applications across the 1.5–30 MHz spectrum. Featuring a 40-meter radiating element and an integrated high-efficiency BALUN, this antenna is the Swiss Army knife of HF systems. It requires no Antenna Tuning Unit (ATU) and no resistors, ensuring that 100% of your transmitter power is available for radiation. Whether deployed for NVIS, ground-wave, or long-distance sky-wave communication, the HFLW-230 is "ready-to-go" right out of the box.

Design: Multirole Frequency Agility

The HFLW-230 is engineered for maximum operational flexibility. Its fully passive design eliminates the need for "knob twirling" or manual measurements. By utilizing a high-performance matching BALUN, the antenna maintains a VSWR better than 2.5:1 across the entire band. Because it does not use terminating resistors, it avoids the power loss common in other broadband wires, making it exceptionally efficient for low-power tactical manpacks and high-power base stations alike.

Construction: Military-Grade Resilience

Built to survive the rigors of the field, the HFLW-230 features a 40-meter radiating element made of high-quality insulated copper or Type 303 marine-grade stainless steel. The matching BALUN is housed in a rugged Nylon enclosure, vacuum-sealed to be 100% weatherproof. All mechanical fasteners are made of Type 316 stainless steel, ensuring immunity to salt fog and acid rain. The antenna is lightweight (4.5 Kgs) and can be fully deployed by a team of two in under 5 minutes.

Reliability: Tactical Configuration Mastery

The HFLW-230 can be adapted to almost any field environment through various mounting configurations:

• Horizontal/Sloping Dipole: Ideal for NVIS and medium-range omni-directional coverage.
• Inverted L / Bent Dipole: Optimized for low-frequency ground-wave communication.
• Base-Fed Vertical: Best for long-distance sky-wave and omni-directional ground-wave.
• Inverted V / Sloping V: Directional configurations for long-range tactical links.

The system is completely D.C. grounded, providing integrated protection against lightning and atmospheric static, ensuring your sensitive receivers remain "quiet" and protected.

Technical Features

• Full 1.5–30 MHz Bandwidth: Instantaneous frequency access; no ATU or manual tuning required.
• No-Resistor Efficiency: 100% of RF power is radiated for maximum signal reach and battery life.
• Multirole Deployment: Can be configured as a Sloper, Inverted V, Inverted L, or Vertical.
• Rapid 5-Minute Setup: Designed for high-mobility tactical teams and emergency response.
• MIL-STD-810G Compliant: Certified for extreme temperatures, salt fog, shock, and heavy rain.
• Marine Grade 303/316 Hardware: Total corrosion resistance for coastal and shipboard use.
• 250W CW Power Handling: Robust electrical design for continuous duty transmissions.
• D.C. Grounded Architecture: Superior lightning protection and noise immunity.
• Compact Logistics: Fits in a small 0.3m box; ideal for tactical kits and airborne deployment.
• User-Serviceable BALUN: Can be removed with simple hand tools without dismantling the wire.

Tactical Deployment Guide: 3.5 MHz Nighttime NVIS Optimization

To maximize the performance of the HFLW-230 for regional nighttime links (0–500 km) on the 3.5 MHz (80m) band, you must optimize the "Take-Off Angle." Unlike long-distance communications that require height for a low horizon fire, NVIS (Near Vertical Incidence Skywave) requires the signal to go straight up.

1. The 1/4 Wavelength Rule for NVIS

For NVIS to be effective, the antenna must be mounted at a height that allows the ground-reflected wave to reinforce the upward-traveling wave.

• The Calculation: At 3.5 MHz, a full wavelength is approximately 85 meters. The optimal height for NVIS is between 0.1lambda and 0.25lambda.
• Optimal Height: For the HFLW-230, this means mounting the 40-meter wire at a height of 8 to 15 meters (26 to 50 feet).
• The Physics: If the antenna is too high (above 20 meters), the pattern "splits," creating a null directly overhead, which creates a "skip zone" where you cannot hear local stations. If it is too low (below 5 meters), the ground absorbs too much of the signal.

2. Configuration: The "Horizontal Sloper"

While the HFLW-230 can be a vertical, for 3.5 MHz NVIS, a Horizontal or Sloping Dipole configuration is superior.

• Setup: Fix the BALUN end to a mast at 10 meters and the far end of the 40-meter wire to another support at the same height.
• Result: This creates a broad, high-angle "lobe" that saturates the ionosphere directly above the station, allowing your signal to "rain down" over the entire region, regardless of mountains or dense forest.

3. Grounding: The 40-Meter Counterpoise

Since the HFLW-230 is a long-wire system, it is only "half" of the antenna. The ground is the other half.

• Direct Grounding: Always bond the N-Female connector shield or the BALUN’s ground terminal to a high-quality ground rod.
• The "Magic" Radial: If the soil is dry or rocky (poor conductivity), lay a single 40-meter wire on the ground directly beneath the main antenna wire. This acts as a "reflector," bouncing the signal upward and increasing your NVIS efficiency by up to 3 dB.

4. Nighttime Frequency Management

At night, the ionosphere’s "D-layer" disappears and the "F-layer" thins. This makes higher frequencies (above 7 MHz) pass through into space.

• 3.5 MHz Strategy: The HFLW-230’s 40-meter length is nearly a half-wavelength at 3.5 MHz, making it highly efficient.
• No-Tuner Advantage: Because the HFLW-230 is inherently broadband, you can stay on your 3.5 MHz nighttime frequency and instantly hop to a 7 MHz "gray-line" frequency as the sun rises without needing to recalibrate an ATU.

NVIS Deployment Checklist