The B3D is deliberately simple at the operating position: choose the wire length that fits the property and frequency range, raise the center, spread the two equal legs, connect 50-ohm coax, and let a suitable tuner finish the match on the bands that need it.
That simplicity should not be confused with a small antenna. Even the 60 ft model needs two clear 30 ft legs. The 120 and 146 ft models need correspondingly larger space, but they also extend the documented operating range to 160 meters.
What matters before you buy or deploy
- 60 ft total: two 30 ft legs, documented for 80–6 m.
- 120 ft total: two 60 ft legs, documented for 160–6 m.
- 146 ft total: two 73 ft legs, documented for 160–6 m.
- Deploy as an inverted-V with one center support or as a horizontal dipole with center and end supports.
The three documented sizes
- 60 ft total: two 30 ft wire legs for 80–6 m.
- 120 ft total: two 60 ft wire legs for 160–6 m.
- 146 ft total: two 73 ft wire legs for 160–6 m.
Operating boundaries
- Published power: 100 W SSB, 50 W CW, and 25 W for digital, RTTY, AM, FM, and other high-duty-cycle modes under ICAS conditions.
- Published typical SWR: 4:1 or less, depending on model, configuration, height, site, and frequency; use a suitable tuner on most frequencies.
- Use the selected model only as an inverted-V or horizontal dipole under the current guide.
- Connector fit does not approve an undocumented wire, transformer, support, or power level.
Make the next setup repeatable
Record model length, center height, endpoint heights and bearings, support hardware, feed line, choke location, tuner state, analyzer reference plane, weather, and on-air reports. Those details explain more than a single station-end SWR value.
This page makes the operating decision easier to understand. The current guide still controls assembly order, dimensions, power limits, and safety.
