Build a Sloping V Antenna
A Sloping V is a favorite low-band DX tool for stations with just one tall support: two wires fed together near the top, both sloping down and out toward your target DX direction rather than laid out level between three separate supports like a horizontal Vee Beam. The slope itself does real work — combined with ground reflection, it concentrates radiation at a low angle toward the direction the wires point, making it a genuinely effective single-tower DX antenna on 160m and 80m. This guide covers the complete build from leg length and included angle through feedpoint assembly and tuning.
Not the Same Antenna as a Horizontal Vee Beam
This site's Vee Beam guide covers a large, level, three-support long-wire antenna fed at an apex between two far-end supports of similar height, giving a bidirectional pattern along the V's bisector. A Sloping V is a different, more compact concept: fed from the top of a single tall support (a tower, tall mast, or tree), with both legs running down and outward at an angle toward roughly the same target direction. The slope and the ground beneath it become part of the antenna's directional behavior in a way the level Vee Beam doesn't rely on.
Why the Slope Adds Directivity
A vertical or sloping wire over real ground develops a directional pattern favoring the low-angle direction the wire leans toward, due to how the direct and ground-reflected waves combine — the same general mechanism that makes a simple 160m/80m sloper a popular single-wire DX antenna. Combining two such sloping wires into a V, both angled toward the same general heading, reinforces this favored-direction behavior while the V geometry itself adds some of the same current-combining benefit a Vee Beam gets from its two legs.
Choosing Leg Length and Included Angle
Shorter legs (around 0.5λ) are the most practical starting point for most stations, keeping the far ends at a manageable height and distance from the base of the support. Longer legs (approaching 1λ or more) add gain but require considerably more room and higher far-end support points.
- Included angle: 60-90° between the two legs is a common practical range for a 0.5λ sloping V — narrower than the wide angles a horizontal Vee Beam's much longer legs would use.
- Slope angle: aim the wires down at roughly 30-45° from horizontal, low enough to get real ground interaction benefit but not so low that the far ends nearly touch the ground before reaching full leg length.
Unterminated vs. Terminated
Left unterminated, the Sloping V is a simple resonant antenna fed with ladder line to a tuner, with the directional favoring coming mostly from the slope/ground interaction described above. Adding termination resistors at both far ends (matched to the wire's characteristic impedance, similar to a terminated rhombic or vee beam) converts it into a traveling-wave antenna with a cleaner, more strongly unidirectional pattern at the cost of dissipating roughly half the transmitted power in the resistors — a tradeoff most builders accept only when the improved pattern and reduced backscatter genuinely matter for their operating goals.
| Band | Leg length (ft) | Minimum support height | Notes |
|---|---|---|---|
| 160m (1.9 MHz) | 246.3 ft | 60+ ft | A serious commitment antenna — needs a tall tower and significant ground area |
| 80m (3.75 MHz) | 124.8 ft | 50+ ft | The most common band for this design among low-band DXers |
| 40m (7.15 MHz) | 65.5 ft | 40+ ft | Workable, though a full-size vertical often outperforms this at 40m |
Sloping V Calculator
Materials for a complete Sloping V build
Building the Sloping V Antenna
This guide builds the simpler unterminated (resonant) version, fed with ladder line to a balanced tuner.
Choose Your Target DX Direction
Decide on the compass heading you most want to favor — this determines which direction both legs will slope toward from your support.
Install the Top Feedpoint
Mount a feedpoint insulator/junction as high as practical on your support — the higher the feed point, the better the slope angle and ground interaction typically work out.
Mark the Two Far-End Anchor Points
Using your target heading and the included angle from the calculator, mark two ground (or low-support) anchor points that put both legs at the correct length and angle, both roughly toward your chosen direction.
Cut and Run Both Legs
Cut two equal-length wires per the calculator and run them from the top feedpoint down to each far-end anchor, maintaining the target slope angle and included angle between them.
Terminate the Far Ends
Attach end insulators at both anchor points. For the unterminated version, simply secure the wire ends here. For a terminated version, install a non-inductive resistor from each wire end to a ground rod at that anchor point instead.
Connect the Feedline
Connect ladder line at the top feedpoint and route it down the support to the shack, keeping it clear of metal structures along the way.
Tune and Verify
Connect the feedline to your balanced tuner and find a low-SWR setting at your target frequency.
| Symptom | Most likely cause | Diagnosis | Fix |
|---|---|---|---|
| No noticeable directional favoring toward the target heading | Slope angle too shallow, or feedpoint not high enough on the support | Check the actual slope angle and feedpoint height against the design guidance | Increase feedpoint height or steepen the slope angle if the site allows |
| Tuner can't find a match | Feedpoint or wire connection fault | Check continuity through both legs and the feedline | Re-solder connections; verify no shorts at the feedpoint junction |
| Unequal performance between the two legs | Legs at different lengths or slope angles | Measure both legs' actual length and angle against each other | Correct whichever leg is off from the calculated dimensions |
| Terminated version shows no directional improvement over unterminated | Wrong termination resistor value, or resistor not properly grounded | Check resistor value against the wire's characteristic impedance and verify the ground connection | Correct the resistor value; ensure a solid ground rod connection at each termination point |
| SWR shifts with weather | Ladder line spacing affected by ice or wet conditions | Check feedline spacing after weather events | Use commercial ladder line with stable dielectric spacing |
How is this different from the Vee Beam already on this site?
The Vee Beam is a level, three-support long-wire antenna fed at an apex between two similar-height end supports, giving a bidirectional pattern. A Sloping V is fed from the top of just one tall support, with both legs sloping down toward the same general direction — the slope and ground interaction, not just the V geometry, are what create the favored direction here.
Do I need a tower for this, or can any tall support work?
A tower is common because many low-band DXers already have one, but any sufficiently tall support — a tall mast, a tree with a suitable pulley, or a guyed pole — can work, as long as the feedpoint sits high enough for a useful slope angle.
Is this a transmit antenna, a receive antenna, or both?
Both — unlike the EWE, Pennant, and Flag antennas on this site, the Sloping V is a full transmit-capable antenna, typically run at normal transmitter power levels through a tuner.
Should I terminate it or leave it unterminated?
Most builders start unterminated — it's simpler, and the slope/ground-interaction directivity is already meaningful without termination. Add termination resistors later if you specifically want the cleaner, more strongly unidirectional pattern a traveling-wave feed provides and are willing to accept the power dissipated in the resistors.
Can I build two Sloping V's for different directions?
Yes, some stations build multiple sloping V's from the same tower aimed at different DX headings, switched at the shack — the same approach used with simple single-wire slopers.
What if my property doesn't allow the full leg length?
Shorter legs (down toward 0.25λ) still function as a directional sloper-style antenna, just with reduced gain and directivity compared to the 0.5λ reference design — a legitimate compromise if a full-length build doesn't fit your site.