Smarter Receive Arrays for Every Band

Last updated: August 22, 2025.

Two Design Philosophies: Low‑Q Parasitics and Fixed Phasing

Our receive arrays are built on two complementary concepts. The first is low‑Q switchable parasitics — broadband passive elements with deliberate damping so patterns stay consistent across frequency, weather, and soil. The second is fixed‑hybrid phasing — stable, multi‑direction beamforming without relays, tuners, or phase‑line trimming. Together they deliver instant directional control, high RDF, and excellent noise rejection, without constant re‑tuning.

Parasitic arrays (EchoArray, VortexArray) use a single active center surrounded by electronically switched passive elements to steer the beam. Each passive element can be set as a director, reflector, absorber, or made effectively invisible when powered off. Fixed‑phased arrays (EchoTriad, QuadraTus, WaveQuad) use broadband hybrids to produce multiple beams simultaneously with phase stability that doesn’t drift over time or temperature.

PolarFlip: Boosting NVIS with Polarization Diversity

The PolarFlip (1–8 MHz) combines two cardinally oriented low‑band RX antennas — e.g. TerraBooster, OctaLoop, or SkyTracer — through a 90° hybrid to produce LHCP and RHCP outputs. On NVIS paths (160–40 m), selecting the correct hand can yield ~6–12 dB improvement during polarization fades. For diversity, monitor LH and RH simultaneously on dual receivers for rock‑steady copy.

EchoTriad: Six Directions Without Switching

The EchoTriad uses three EchoTracer vertical e‑field probes in an equilateral triangle. Fixed ±45° hybrids give six primary directions instantly — no switching. Thanks to the geometry and feed method it maintains useful RDF across bands, making it a practical multiband array from 30 m up to 10 m. High CMRR and low noise make it ideal for DX. Typical 3‑band sets: 30‑20‑17, 20‑17‑15, 15‑12‑10.

EchoTriad — Geometry (equilateral triangle)

      A
     / \
    /   \
   /     \
  C-------B
  

EchoTriad — Target Direction & Feed

To receive East:       B = 0°,  C = +45°, A = –45°  → null points West
To receive North:      A = 0°,  B = +45°, C = –45°  → null points South
To receive South:      C = 0°,  A = +45°, B = –45°  → null points North
To receive West:       A = 0°,  C = +45°, B = –45°  → null points East
To receive Northeast:  C = 0°,  B = +45°, A = –45°  → null points Southwest
To receive Southwest:  B = 0°,  A = +45°, C = –45°  → null points Northeast
  

QuadraTus: 4‑Square Low‑Band Power

The QuadraTus uses four VerticalVortex elements in a square with a fixed ±45° polyphase core, presenting all eight directions at once — no switching. It’s optimized for 160 m and 80 m; with careful siting it also provides usable 40 m performance.

QuadraTus — Geometry (square, 4 VerticalVortex)

A----B
|    |
|    |
D----C
  

QuadraTus — Target Direction & Feed

To receive North:      A = –45°, B = 0°,   C = +45°, D = 180°
To receive Northeast:  B = –45°, C = 0°,   D = +45°, A = 180°
To receive East:       C = –45°, D = 0°,   A = +45°, B = 180°
To receive Southeast:  D = –45°, A = 0°,   B = +45°, C = 180°
To receive South:      A = +45°, B = 180°, C = –45°, D = 0°
To receive Southwest:  B = +45°, C = 180°, D = –45°, A = 0°
To receive West:       C = +45°, D = 180°, A = –45°, B = 0°
To receive Northwest:  D = +45°, A = 180°, B = –45°, C = 0°
  

EchoArray: Switchable Parasitic Crown for 20–10 m

The EchoArray places a central EchoTracer e‑field probe inside one or two concentric rings of four ground‑mounted parasitic elements. Each parasitic is a 6 m aluminum tube with floating on‑ground radials to keep impedance consistent. A low‑voltage control hub drives small switching networks at each element so a parasitic can function as director, reflector, absorber, or be made effectively invisible when powered off.

EchoArray 20–17 m (Outer Crown)

• Radius: ~3.4 m (≈0.25–0.30 λ at 14–18 MHz).
• Optimized for: 20 m and 17 m; still effective on 15 m.

EchoArray 15–12–10 m (Inner Crown)

• Radius: ~1.8 m (≈0.17–0.27 λ at 28–21 MHz).
• Optimized for: 10 m, 12 m, and 15 m.

EchoArray — Plan View (top)

        N
      P(N)
        |
P(W) --  •  -- P(E)      • = EchoTracer (active)
        |
      P(S)               P(x) = Parasitic (director/reflector/absorber/neutral)

Outer crown radius ≈ 3.4 m (20–17 m)
Inner crown radius ≈ 1.8 m (15–12–10 m)
Parasitic: 6 m aluminum tube + floating on‑ground radials
  

Two Crowns, One Hub

Install both crowns on the same mast: the outer (3.4 m) for 20–17 m and the inner (1.8 m) for 15–12–10 m. Keep separate floating radial sets, azimuth‑offset the inner ring by ~45°, and add ~0.8–1.0 m vertical stagger. Park the idle ring in a neutral high‑Z state to minimize coupling. Control both via choked Cat5 pairs from the logic hub.

VortexArray: 40 m Parasitic Crown

The VortexArray adapts the same method to 40 m, with a central VerticalVortex surrounded by four parasitics at a radius of ~8–9 m (≈0.21–0.24 λ). Each parasitic is a 6 m ground‑mounted tube with floating radials. The active center is bonded to ground for a stable reference.

VortexArray — Plan View (top)

        N
      P(N)
        |
P(W) --  •  -- P(E)      • = VerticalVortex (active)
        |
      P(S)               P(x) = Parasitic (director/reflector/absorber/neutral)

Crown radius ≈ 8–9 m (40 m)
Parasitic: 6 m aluminum tube + floating on‑ground radials
  

WaveQuad: Traveling‑Wave Beverage Array

The WaveQuad is the phasing system for four PulseRoot100 elements — active, dynamically terminated 100 m Beverages‑on‑Ground. A central hub feeds the four arms at 0°/±90°/180°, delivering all eight directions simultaneously — near the performance of eight individual Beverages with only four runs. (PulseRoot100 & WaveQuad are in active development/testing.)

WaveQuad — Hub‑Fed Traveling‑Wave Geometry

          A (North)
            |
            |
            |
D (West) ---H--- B (East)
            |
            |
            |
          C (South)

H = central phasing hub (0° / ±90° / 180°)
Each arm = PulseRoot100 traveling‑wave element; wave travels outward to a resistive termination at the far end
  

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