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Sail Rigged Utility Antenna
6 through 20 meters

by Dick Reid,  KK4OBI
 Two 27-inch telescoping antennas1 on a wooden pole (Figure 1) clamped to a picnic table, RV ladder, balcony rail or vehicle is all you need. Extend the telescopes, connect the coax and you are on the air. No radials. No tuner. Nearly perfect SWR on any part of the 6, 10, 12, 15, 17 and 20 meters bands.

Here is how it works.  How to make one.  How to use it.


Stainless steel telescoping antennas have been around a long time. The various versions have been touted for building collapsible, multi-band antennas. Of particular interest is the 17 foot model. From only 27” long, it can tune any band between 6 and the 20 meters as it is extended. And best of all, a pair of these eliminates radials by forming a half-wave antenna.

The easiest half-wave configuration (and the most compact) is to have one telescoping arm mounted vertically and the other arm pivoting to the side in an “L” shape. This is a bent dipole where the mixed radiation pattern is like a vertical but also has horizontal gain because of RF concentrated in the direction of the side arm.2

The problem is: How do you support a drooping telescopic antenna when it is up to 17 feet long?

This where sail rigging comes in. The vertical arm of the antenna is secured to a mast. A line (halyard) runs up to the top of the mast, through an eye and down to support the antenna side arm (boom).

Sloop Sail RiggingSail Rigged Antenna

In this way the side arm is easily adjusted to any angle.

The halyard line is then secured to a cleat on the mast.


Because the antenna is a half-wave, the total length of the two arms determines the frequency. The calculated length will be close to the desired frequency. Fine tuning is conveniently done by adjustments to the length of the side arm. It is not necessary to have the arms of equal length. However, a common code choke is advised, particularly if: (1) operating far from resonance, (2) feeding far from center,

Fine tuning also includes adjusting the Standing Wave Ratio, SWR.

L-Antenna Angle vs ImpedanceGenerally the impedance of a straight resonant center-fed dipole is around 70 Ohms. Whether the dipole is horizontal or vertical makes little difference.
70 Ohms gives a good match for 50 Ohm coaxial cable.  Something  in the neighborhood of 70/50 = 1.4 SWR.

If the lower half of a vertical dipole antenna is raised to a horizontal position, the impedance falls to roughly 35-40 Ohms. Somewhere in between there is the best match a 50 Ohm feed line.

Note that changing the angle also changes the frequency slightly. By alternately adjusting frequency and angle there can be found a point of minimum SWR or minimum reactance (antenna analyzer).

Tall and Wide Configurations to Tailor Characteristics

Because the telescoping arms can be different lengths, this makes it possible to emphasize vertical or horizontal characteristics of antenna radiation. This depends on frequency and height over ground.

If you cannot get the antenna very high, need a smaller antenna or want to talk to another vertical antenna, consider this: By lengthening the vertical arm there can be found a match for coax by shortening the side arm to maintain the total length for resonance. The taller the vertical arm, the more the antenna is like a vertical. About 75%/25% vertical/side half wave ratio is possible however the sweet-spot for best match is around a 60%/40% ratio. This is a Tall L-Antenna.3

Note: Signals will be noticeably stronger to and from the side with the side arm

If you can get the antenna up 1/3 to 1/2 wavelength high, this where the figure-8 directional gain of a horizontal dipole develops. To emphasize this horizontal gain characteristic, consider using a long side arm with a 60%/40% to 75%/25% side/vertical half wave ratio. This is a Wide L-Antenna.4

Note: a tall or wide configuration is not possible for 20 meters where both telescoping arms are already at maximum length.

Dipole Configurations give the best signal strength

If you can not get height, then you want the no-radial, low-angle, circular radiation of a vertical dipole. Merely point the side arm down. Take care to lead the feed line away as closely to horizontal as possible to minimize the coax coupling with the antenna. Tuning and SWR are affected because one end is closer to ground. Because of this, get as much clearance from the ground as possible. Fine tune by adjusting antenna length to get the desired frequency and by antenna angle for lowest SWR.

A horizontal dipole (Figure 5) is best.. If you can get the antenna feed point up approaching a 1/2 wavelength high, that is... around 9 ft at 6 meters, 17 ft. at 10 meters or 21 ft. at 15 meters. This is where the directional characteristics and full gain of a horizontal dipole work in your favor. 

How to configure a horizontal dipole:

Horizontal Dipole Configuration

1. Use the sail rig to position the side arm horizontally and secure the halyard to its cleat.

2. Release the vertical arm and halyard. Pivot this arm to horizontal and secure the sail rig halyard to its cleat. This forms a sideways L with the side arm pointing forward.

3. Swivel the side arm to align the two arms into a horizontal dipole.

Take care to lead the feed line down as closely to vertical as possible. A 90 degree coax connector is desirable. Adjust antenna length for the desired frequency. A 1:4 SWR is very good for a horizontal dipole.

Droop has no detectable effect and is compensated by the sail rig. As usual, angle adjusts SWR.


Swivel Link A swivel link (Figure 6) between the two telescoping whips is the key detail. This link is made from 1-1/2” x 1-1/2” x 1/8” thick Aluminum Angle stock. Use two sections 1-1/8” wide.

As can be seen, the swivel side is shortened to 1” and rounded. Connection is by a #10 x 1/2” Stainless Steel (SS) machine screw, washers(2) and lock nut. Spacing between whips is 1-3/4” on centers.

The upper whip connection uses a 3/8” x 24 nut and washer.

The lower whip connection uses a SO-239 to 3/8” x 24 Threaded Stud antenna mount adapter.

The antennas are connected to the mast by the stud mount adapter using a #0 ACC conduit and pipe hanger pivot (figure 8). A 3/8” x 1” washer is used (as shown) between this adapter and the whip to prevent slippage when the antennas are clamped in the pipe hanger pivot.

Be sure that there is whip continuity between the stud mount adapter and the center pin of the coax connector… and that there is no connection to the other whip.

A holder block on the top of the mast secures the whips when not deployed (Figure 1).

The holder is made from a 3” x 3” x �” wood base and (2) �” x 5/8” x 3” side strips and a 7/8” x 5/8” x 3” center strip.

The lock-hooks are from �” x �” aluminum angle pieces 1-1/2” long (2). The vertical edge is removed except for a �” section at the hook end which provides a lifting tab.

Blick and Halyard Eye
For the sail rig lines (halyards), a brass grommet is attached as shown to a 1-1/8” x 2-1/2” x 0.1 piece of Lexan or similar plastic. This piece is screwed to the back of the holder block.

It is left to the builders’ ingenuity on how to attach the block to the mast inline with the coax-fed whip.

The final parts of the sail rig mast are the cleats for the lines and the pivot to make a horizontal dipole.

Antenna Pivor and Pivot
The pivot is a #0 ACC Conduit and Pipe hanger mounted 21” from the top of the mast and in-line with the holder block.

To attach the two whips, the Threaded Stud Antenna Mount adapter of the antenna assembly is placed in the Pipe Hanger. The two whips are aligned with the holder block. The Pipe hanger is tightened securely on the Threaded stud

The 3” nylon cleats are mounted as shown.

Final assembly: Rig the sail.

The side arm swings from up to down. To do this requires 84” (7’) of line. The vertical arm pivots only horizontally to form a dipole. It needs only 70” (5’ 10”) of line.

PVC Tiewraps on WhipEach line is tied to a �” section of �” PVC pipe. This pipe piece is used to attach the lines to the telescoping whips.

Two 4” cable ties are looped through the pipe piece. These will reduce the internal diameter so that the pipe stops at the end of the second telescoping section at 38”.

The bitter-end of the line goes up through the grommet eye and down to a cleat on the mast to complete the rigging.

Mounting the antenna

Mounting using the antenna mast alone is ok but expect limited results. Ground loss is higher and your signal goes more upwards. It is better get the antenna higher by inserting the antenna mast into a tall tube (telescoping) or clamping it onto a pole.

The pole or tube can be supported by a house, vehicle, table, fence, balcony rail or a tripod secured to the ground. Whatever the situation you will want to be able to reach (ladder, table) the halyard and cleats on the mast and be able adjust the length and angle of the side arm while looking at your antenna analyzer. Fine tuning at a lower level then raising the antenna will lead to many up-down cycles because tuning changes with height.

Mounting a common mode choke near the feed point is not necessary but the choke generally makes your tuning easier because you can touch the cable or antenna analyzer without affecting the frequency or impedance.

Using the antenna

Using the antenna involves selecting the band, deciding the dipole form, setting lengths then fine tuning for frequency and SWR.

Twenty meters is a special case. The telescoping whips are not long enough to cover the entire 20 meter band down to 14.000 MHz. An extension of wire wrapped around or clipped to the end of the whips is required. Wire direction is not critical. Straight or to the side, either is good. Start with around one foot long. Folding back and adjusting whip length and angle is how to fine-tune frequency.

Alternate solution: Replace the side whip with a 20 meter Hamstick-type loaded antenna. This reduces the length from 17 feet to 7 feet. This eliminates the need for an extension on the vertical whip, tunes the entire 20 meter band and makes easier to reach up and adjust its length.

The following table of values is useful to set a starting lengths depending on the antenna form used.

Sail Rigged Utility Antenna

Dimensions for the 6, 10, 12, 15, 17, and 20 meter bands

Based on feed point elevation of 20 feet (6 Meters)

Vertical-to-Arm ratios are: Wide-L = 40/60, Equal-L = 50/50, Tall-L = 60/40

Table of dimension

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Dick Reid, KK4OBI at QSL.net