Classic Hexbeam - Basics
1. Introduction
The Hexbeam is an innovative antenna. By bending the Driver and Reflector wires into "M" and "W" shapes, respectively, it manages to achieve useful beam performance in a turn radius about one half that of a full-size 2-element Yagi. Traditionally it has been constructed of wire elements strung on fibreglass support spreaders. By "bowing" the spreaders upwards, wires for several bands can be supported at different heights; this allows a multi-band Hexbeam to be constructed without any of the normal compromises such as resonant traps, and it preserves a consistent Driver / Reflector geometry on each band.
We refer to this traditional Hexbeam design as the "Classic" to distinguish it from the new G3TXQ Broadband Hexbeam. Although the Classic has a limited performance bandwidth compared to the newer design, it has a 15% smaller turn radius, and this may make it the more attractive choice in space-critical situations. It would, for example, make an attractive antenna for 30m or 40m where size is likely to be an overriding factor, and where the narrow bandwidth is less problematic because of the size of the band allocations.
2. Design details
| Classic Hexbeam Dimensions - CW portion | |||||
|---|---|---|---|---|---|
| 20m | 17m | 15m | 12m | 10m | |
| Driver (half-length) | 216" | 166.9" | 142.8" | 121.1" | 107.7" |
| Reflector (half-length) | 220.5" | 170.3" | 145.7" | 123.6" | 109.9" |
| Driver end spacing | 7.7" | 6.1" | 5.4" | 5.4" | 5.6" |
| Reflector end spacing | 5.0" | 4.0" | 3.6" | 3.6" | 3.6" |
| Vertical spacing from baseplate | 42" | 20" | 14" | 10" | 6 |
| Classic Hexbeam Dimensions - SSB portion | |||||
|---|---|---|---|---|---|
| 20m | 17m | 15m | 12m | 10m | |
| Driver (half-length) | 213.6" | 166.9" | 141.4" | 121.1" | 106.2" |
| Reflector (half-length) | 218.0" | 170.3" | 144.2" | 123.6" | 108.4" |
| Driver end spacing | 7.7" | 6.1" | 5.4" | 5.4" | 5.6" |
| Reflector end spacing | 5.0" | 4.0" | 3.6" | 3.6" | 3.6" |
| Vertical spacing from baseplate | 42" | 20" | 14" | 10" | 6 |
These tables show the recommended dimensions for a 5-band Classic Hexbeam constructed from #16 bare copper wire. Because the antenna is relatively narrow-band, alternative dimensions are recommended for the CW and SSB portions of the wider amateur bands. The band feedpoints are interconnected with 50 Ohm coax, and the array is Top fed. The design has now been adopted by a significant number of constructors, and these dimensions are proving to be robust and repeatable.
Although this site contains some photographs of my own Classic HexBeam, it does not provide detailed constructional information. If you need guidance on making one, you should visit Leo's (K4KIO) website where you will find excellent step-by-step instructions.