DX Engineering AVA-3 Active Matching Unit

The AVA-3 is a wideband active matching unit that buffers a physically short receive element and transforms it to a 75 Ω feedline, enabling exceptionally quiet reception from VLF through HF. It’s the core amplifier used in DXE’s Receive Short Element Active Verticals (RSEAV).

Highlights

• Wideband coverage: practical 40 kHz–30 MHz when installed as recommended.
• Strong-signal handling: +39 dBm TOI for tough RF environments.
• Selectable gain: internal jumpers for −6 dB (default), 0 dB, or +6 dB.
• Consistent response: flat gain with tight unit-to-unit match — ideal for arrays.
• Flexible power: built-in Bias-T over RF coax or separate Direct DC F-connector.
• Optimized for short elements: ~1.8–7.3 m (6–24 ft) whips or wires.

Ideal for

• Low-noise RX on 2200 m, 630 m, MW/AM BCB, and 1.8–30 MHz HF
• Contest RX antennas, DXpeditions, 2/4/8-element arrays, skimmers, remote RX sites

What you’ll need

• Short RX element ≈1.8–7.3 m (common: ~2.6 m / 8.5 ft 3-section whip)
• 75 Ω RG-6 (quad-shield recommended) — outdoor/flooded if direct-bury
• 12–15 V DC, ~25 mA (Bias-T or Direct DC)
• Good RF ground; clear area away from towers/metalwork

Operator tips

• Start with the lowest gain that still lifts the band noise above your receiver’s noise floor.
• Use Direct DC powering for operation below ~100 kHz or for always-on skimmers.

Key Specifications

What’s in the box

• AVA-3 Active Matching Unit (DXE-AVA-3)
• Note: Whip, plate, and ground hardware are included with RSEAV kits (sold separately).