The Yaesu ATAS-120A is a patented, professional-grade Active Tuning Antenna System (ATAS™) engineered for high-performance mobile amateur radio installations. Offering unmatched multiband versatility, this unique vehicular antenna provides continuous motorized tuning across key High Frequency (HF), Very High Frequency (VHF), and Ultra High Frequency (UHF) amateur bands. It is the premier choice for mobile operators demanding a single-antenna solution capable of executing rapid frequency adjustments on the move without the hassle of manual element swapping.
Designed for seamless integration with ATAS-compatible Yaesu transceivers, the antenna utilizes microprocessor-controlled DC signaling sent directly through the feeding coaxial cable. This internal drive system automatically adjusts the physical length of the antenna’s radiator to achieve the lowest possible Standing Wave Ratio (SWR) on any selected frequency. The ATAS-120A covers the 7, 14, 21, 28, 50, 144, and 430 MHz (40/20/15/10/6/2 meters and 70 cm) amateur bands, rendering it fully plug-and-play with iconic transceivers such as the Yaesu FT-857D, FT-897D, FT-891, FT-991, FT-991A, and FT-450D.
Physically, the antenna features an extendable height profile ranging from approximately 4.59 to 5.25 feet (1.4 to 1.6 meters) to accommodate real-time tuning parameters, while weighing a highly manageable 1.98 lbs (900 g) to prevent excessive mechanical strain on heavy-duty trunk lid or bumper mounts. It boasts an input impedance of 50Ω and a robust power handling capacity of 120W SSB/CW (at a 50% duty cycle). When paired with a reliable chassis ground or effective counterpoise system, it delivers a matched SWR of less than 2.0:1, securing clean transmission lines and preserving the lifespan of your transceiver’s power amplifier.
Key Features
- Patented Active Tuning Antenna System (ATAS™) with automatic motorized tuning.
- Comprehensive multiband HF, VHF, and UHF amateur band coverage (7/14/21/28/50/144/430 MHz).
- No separate control cable required; microprocessors send control signals over the existing coaxial line.
- Directly compatible with leading mobile and base-station Yaesu transceivers.
- Solid power handling up to 120 Watts (SSB/CW) for dependable DX communications.
- Adjustable vertical height controlled dynamically by the radio’s internal tuning commands.
Technical Specifications
| Parameter | Specification |
|---|---|
| Brand | Yaesu |
| Model Designation | ATAS-120A |
| Antenna Type | Active Motorized Mobile Multiband Antenna |
| Operational Bands | 40, 20, 15, 10, 6, 2 meters and 70 cm (7 / 14 / 21 / 28 / 50 / 144 / 430 MHz) |
| Maximum Power Capacity | 120 Watts (SSB / CW, 50% duty cycle) |
| Matched VSWR | Less than 2.0:1 (requires appropriate grounding/counterpoise) |
| Nominal Input Impedance | 50 Ω |
| Compatible Transceivers | Yaesu FT-857D, FT-897D, FT-891, FT-991, FT-991A, FT-450D |
| Approximate Height | 4.59 to 5.25 ft. (1.40 m to 1.60 m) |
| Approximate Weight | 1.98 lbs. (900 g) |
Package Content
- 1x Yaesu ATAS-120A Active Tuning Mobile Antenna
- 1x Weatherproof Rubber Cap Assembly
- 1x Wrench and Hardware Installation Pack
- 1x Detailed User Reference Manual
