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Call 0345 2300 599The OptiBeam OB11-3HD is a high-performance heavy-duty triband Yagi antenna designed for the 20m, 15m, and 10m amateur radio bands.
Covering 14, 21, and 28MHz, the OB11-3HD is engineered for demanding operators who want strong gain, excellent pattern control, low SWR, and robust long-term reliability from a serious fixed-station HF beam.
The antenna uses a direct-coupled 3-element driver cell, with the drivers interconnected by a phase line of square tubes. It also features dedicated reflectors for each of the three bands, separate directors for 20m and 15m, and three directors for 10m. This carefully optimised layout helps maximise gain, maintain pattern stability, and provide strong front-to-back performance across the supported bands.
With a 5kW power rating, included balun, SO-239 feed connection, and full-size element design, the OB11-3HD is a serious tribander for DXing, contesting, and high-performance HF station installations.
Key Features
- Heavy-duty 11 element triband Yagi
- Covers 20m, 15m, and 10m
- Designed for the 14, 21, and 28MHz amateur bands
- Full-size element design for high efficiency
- Direct-coupled 3-element driver cell
- Dedicated reflectors for each band
- Separate directors for 20m and 15m
- Three directors for 10m
- Excellent gain and front-to-back performance
- Low SWR across the supported bands
- 5kW maximum power handling
- High-power balun included
- Single SO-239 feed connection
- Horizontal polarisation
- Heavy-duty mechanical construction
- Designed for demanding DX and contest stations
Band Performance
| Band | Gain dBd | Gain dBi | Front-to-Back Ratio |
|---|---|---|---|
| 20m | 5.1dBd | 12.5dBi | 22dB |
| 15m | 5.6dBd | 13.2dBi | 22dB |
| 10m | 6.7dBd | 14.5dBi | 25dB |
SWR Performance
| Band | SWR |
| 20m | 1.2 / 1.0 / 1.3 |
| 15m | 1.4 / 1.1 / 1.5 |
| 10m | 1.4 / 1.0 / 1.5 |
OptiBeam Electrical Design
The OB11-3HD has been developed using advanced computer-aided simulation and refined through practical field testing. The result is a triband antenna designed to deliver high efficiency, excellent bandwidth, stable gain, and reliable radiation patterns across the 20m, 15m, and 10m bands.
The direct-coupled driver cell and full-size element approach help reduce unnecessary losses, while the dedicated reflector and director arrangement provides strong gain and pattern control.
OptiBeam Mechanical Quality
OptiBeam antennas are known for their mechanical strength and attention to detail. The OB11-3HD uses robust aluminium tubing, a strong 40 x 40mm boom, stainless steel hardware, and carefully designed element mounting hardware.
The antenna is designed to maintain correct alignment, resist torsion, minimise element sag, and provide long-term reliability in demanding weather conditions.
Specifications
| Specification | Details |
| Brand | OptiBeam |
| Model | OB11-3HD |
| Product type | Heavy-duty triband HF directional antenna |
| Antenna type | Yagi |
| Supported bands | 20m / 15m / 10m |
| Frequency bands | 14 / 21 / 28MHz |
| Number of elements | 11 |
| Number of connectors | 1 |
| Feedpoint impedance | 50 ohms |
| Connector | SO-239 |
| Balun included | Yes |
| Maximum power | 5,000W |
| Polarisation | Horizontal |
| Maximum element length | 10.96m |
| Boom length | 6.10m / 610cm |
| Boom size | 40 x 40mm |
| Turning radius | 6.25m |
| Wind surface area | 0.84 sq m / 9.0 sq ft |
| Wind load | 669N at 130km/h |
| Weight | 32kg |
| Maximum mast diameter | 50mm |
| Antenna mount | Centre mount |
| Boom guying | Boom guyed twice |
| Strut | No |
Typical Uses
- Fixed-station HF operation
- 20m, 15m, and 10m DXing
- HF contesting
- High-power amateur radio stations
- Operators wanting a serious triband beam
- Permanent mast or tower installations
- Stations needing strong gain and front-to-back performance
Installation Notes
The OB11-3HD is designed for fixed installation on a suitable mast or tower. Please ensure that your mast, tower, rotator, mounting hardware, and support structure are suitable for the antenna’s size, weight, turning radius, and wind load.
As with any HF beam, final performance will depend on installation height, surrounding structures, feedline quality, grounding, and correct assembly.
Important Note
This listing is for the OptiBeam OB11-3HD antenna only. Mast, rotator, coaxial cable, mounting hardware, and other station accessories are not included unless stated otherwise.
Please check that your installation site, rotator, and support structure are suitable before ordering.
Shipping:
We have several shipping options for our products, including next-day and Saturday/Sunday delivery for certain items. Please see these options at checkout.
Returns:
If you have any equipment that needs to be returned to Martin Lynch & Sons, please fill out the form below:
Upon receipt of goods you have 14 days to return goods however the goods must be returned in original packaging and care must have been taken with the goods you wish to return. Under distance selling regulations you are not entitled to any refund on carriage charges or modification charges made at your request. Large items cannot be returned if they have been assembled, unless faulty.
Warranty Terms and Conditions
Outside of the 14 faulty return period, returned items cannot be accepted, unless covered by manufacturer's warranty. We will repair as much as possible on site however in exceptional circumstances products may have to be returned to the manufacturer of distributor.
For repairs/replacements under manufacturer’s warranty for any item please download a ML&S return form from the link above and return to ML&S with the faulty product.
International Warranty information
Warranty service for items we sell is available in the U.K. only, unless otherwise noted. It is your responsibility to pay freight for returned items to the U.K. and back to you for desired warranty coverage. All of our NEW products come with a minimum 12 month warranty, (Yaesu & Icom 24 months), with up to 90 days on second-hand equipment. Items returned for service must state "returned goods for repair" on the return air waybill or U.K. import customs duties apply and will be added to your invoice. For more info about returning items please contact our customer help desk, [email protected]