Guyed masts are frequently used for radio antennas . The mast can either support aerials (for VHF and UHF ) mounted at its top, or the entire structure itself can function as an antenna (for VLF , LF , MF ); this is called a mast radiator . In the latter case, the mast needs to be insulated from the ground . Guyed radio masts are typically tall enough that they require several sets of guy lines, 2 to 4, attached at different heights on the mast, to prevent them from buckling. An exception was the Blaw-Knox tower , widely used during the 1930s, whose distinctive wide diamond ( rhomboidal ) shape gave it the shear strength that it only required one set of guys.
Modern masts form the leading edge of a sail's airfoil and tend to have a teardrop-shaped cross-section. On smaller racing yachts and catamarans, the mast rotates to the optimum angle for the sail's airfoil. If the mast has a long, thin cross-section and makes up a significant area of the airfoil, it is called a wing-mast; boats using these have a smaller sail area to compensate for the larger mast area. There are many manufacturers of modern masts for sailing yachts of all sizes, a few notable companies are Hall Spars, Offshore Spars , and Southern Spars.
1. Secure base and anchors (sold separately).
2. Attach lowered mast to base.
3. Secure guy lines to the lower Guy Ring and attach to anchors. Align the mast vertically by tightening the Guy Lines.
4. Secure upper Guy Ring using the appropriate Mast Clamp to desired location on the upper Tube (see note 8 on page 10).
5. Secure appropriate length guy lines to the upper Guy Ring and let them hang.
6. Raise the upper Tube and inset the cotter pin. Make sure that the cotter pin is inside the notch in the inside tube.
7. Secure the cotter pin and tighten the mast clamp.
8. Secure appropriate length guy lines to the next highest Guy Ring, and let them hang.
9. Raise the next smallest Tube and insert the cotter pin. Make sure that the cotter pin is inside the notch in the inside tube.
10. Secure the cotter pin and tighten the mast clamp.
11. Repeat steps 8-10 until all sections have been raised and are secured.
12. Attach all hanging Guy Lines to their respective anchor. Align the mast vertically by tightening the Guy Lines. Make sure to work your way up the mast while tightening.