The OptiBeam OB11-3HD 11 Element 3-Band Yagi is a high-performance triband antenna engineered for the 14, 21, and 28 MHz amateur radio bands. It delivers exceptional results, offering impressive gain figures and front-to-back ratios, this antenna ensures robust signal control and reliable performance. The OB11-3HD was designed using advanced computer-aided simulation techniques and was fine-tuned through rigorous field testing to achieve optimal performance.

At the core of the antenna is a direct-coupled 3-element driver cell, where the driven elements are interconnected by a phasing line of square tubes. A unique arrangement of dedicated reflectors for each of the three bands along with separate directors for the 20m and 15m bands, and three directors for the 10m band, maximizes gain and pattern stability. By employing this novel feed concept, the meticulous arrangement of elements, and the exclusive use of full-size elements, the OB11-3HD achieves high efficiency and optimal SWR bandwidth.

The OB11-3HD represents a reliable and advanced solution for demanding radio amateurs, delivering exceptional gain, pattern clarity, and power handling in a rugged, precision-built package.

Key Specifications of the OptiBeam OB11-3HD 11 Element 3-Band Yagi:

• Band Coverage: 20, 15 and 10 meters

• Boom Length: 20.0 ft. (6.1 m)

• Longest Element: 36.0 ft. (11.0 m)

• Turning Radius: 20.5 ft. (6.25 m)

• Weight: 70.5 lbs. (32 kg)

• Wind Load: 150.3 lb.-f (669 N) at 80 mph (130 kph)

• Surface Area: 9.0 sq. ft. (0.84 sq. m)

Electrical Performance

Gain:

• 20M: 5.1 dBd (≈12.5 dBi at 20 m height)

• 15M: 5.6 dBd (≈13.2 dBi at 20 m height)

• 10M: 6.7 dBd (≈14.5 dBi at 20 m height)

Front-to-Back Ratio:

• 20M: 22 dB

• 15M: 20 dB

• 10M: 25 dB

SWR:

• 20M: 1.3:1 max.

• 15M: 1.5:1 max.

• 10M: 1.5:1 max.

Feed System:

• Single 50-ohm coaxial line

• Includes choke balun with SO-239 connector

Element Configuration

• 20 & 15M: 3 active elements each

• 10M: 5 elements

Why Choose the OB11-5?

• Wide frequency coverage across the three major HF bands

• High gain and excellent directivity for superior signal performance

• Durable construction rated for harsh weather conditions

• Simplified installation with a single-feed design

OptiBeam's antenna technology has achieved directional antennas with extraordinary electrical properties, including the highest efficiency, optimum band coverage, constant gain, and virtually unchanging patterns across the band, with low SWR. These antennas maintain consistent electrical characteristics under all weather-conditions and include a high power balun with UHF female connector for your 50-ohm coaxial cable.

OptiBeam Antennas are distinguished by their advanced mechanical qualities. Specially configured, stable, and properly shaped element holders, robust square and round booms with effective and solidly built element transitions are hallmarks of OptiBeam quality. They provide advanced physical properties, including proper balance and high stability over the entire system. Elements are perfectly aligned and secured against torsion with minimal sag for a visually pleasing appearance.

OptiBeam antennas are made for those who understand the true value of investing in proven electrical performance and unequalled mechanical quality for the ultimate in reliability. They are built to withstand the harshest conditions using the absolute best materials, including high quality aluminum alloys, UV stable synthetic parts, and stainless steel hardware. OptiBeam antennas are designed to be easier to build than others, often arriving in subassemblies with every part carefully sorted, clearly labeled, and extremely well packed for worry-free shipment and straightforward installation.

For enthusiastic operators of all pursuits, OptiBeam provides the advantage of pure performance. Proven in the field and confirmed by the most demanding hams around the world — OptiBeam is the perfect choice for your station.