What Is Take Off Angle: Simple Guide for Hams

If you’ve ever heard someone on the air say their antenna has a “7-degree take off angle” or seen a modeling plot with mysterious elevation lobes, you might’ve wondered what any of that has to do with making contacts. The truth is simple: take off angle tells you which direction your RF leaves the antenna, and understanding it can completely change how well your station performs—whether you’re chasing local nets or long-haul DX.

Think of take off angle as the “launch direction” of your RF. A 10° take off angle means your signal glides close to the horizon, travels a long distance, and eventually bounces off the ionosphere many hundreds or even thousands of miles away. A 70° angle fires almost straight up, hits the ionosphere quickly, and returns closer to home—a key ingredient for NVIS coverage.

Unlike SWR, it’s not something you can measure directly with a meter. But you can understand it easily with a few rules of thumb, some modeling, and paying attention to the actual geography of your contacts. Once you get the idea, it becomes one of the most practical tools you can use to optimize your station.

What Hams Really Mean When They Talk About Take Off Angle

In ham radio, “take off angle” usually refers to the strongest lobe in your antenna’s vertical radiation pattern. Imagine cutting your antenna pattern in half and viewing it from the side: the horizon is at 0°, straight up is 90°, and somewhere in that slice is the direction where most of your signal energy is concentrated. That direction is your primary take off angle for that band and configuration.

The biggest misunderstanding is thinking take off angle is a fixed number. It changes dramatically with band, ground conductivity, antenna height, and whether your antenna is horizontal, vertical, or some hybrid design. A dipole that’s high enough to be a DX performer on 20 meters might behave like an NVIS antenna on 40 meters—without moving a single inch.

So instead of chasing exact degrees, think in categories: high angles for regional, low angles for DX, and anything in-between for general operating. Real-world antennas almost always produce multiple lobes anyway, and propagation determines which lobe actually gets used at any moment.

How to Actually Understand Your Station’s Take Off Angle

You don’t need advanced tools or deep RF theory to get a practical feel for your take off angle. A few simple checks and some on-air observations will give you insight that’s far more valuable than a single number in a modeling file.

• Step 1: Look up a NEC model (or use an online calculator) for your antenna at different heights. This shows how elevation lobes move as height changes.
• Step 2: Compare those results to your real installation. A horizontal antenna below ~0.3 wavelengths produces higher angles; above ~0.5 wavelengths, lower angles become dominant.
• Step 3: Check your logs. Are most strong contacts nearby? Are distant stations louder on certain bands or times? This reveals your effective angles better than theory alone.

Software like 4NEC2 and EZNEC will show the lobes and angles clearly, but even simple web tools reveal the same pattern: raising a horizontal antenna lowers the main lobe, while vertical antennas generally emphasize low angles automatically—especially with a strong radial system. This is why a vertical in a small yard can often outperform a low dipole for DX even at QRP power levels.

If you’re still experimenting with antennas, the Antennas section and Getting Started guides on Broken Signal offer background that pairs perfectly with understanding take off angle. Once you connect the dots between lobes and propagation, station design gets a lot more intuitive.

Vertical vs Horizontal Antennas and Take Off Angle

“Verticals are for DX and dipoles are for locals” is a common saying, but it’s only partly true. Both styles can produce low or high angles—it all depends on height, ground, and geometry.

• A quarter-wave vertical with a healthy radial field usually produces a strong low-angle lobe, often below 20°, making it excellent for DX.
• A horizontal dipole at half a wavelength or higher also generates solid low-angle radiation—even though many hams assume dipoles are only good for regional work.
• A very low horizontal antenna (like a 40m dipole at 10–20 feet) will produce predominantly high-angle radiation—perfect for NVIS, not for long-haul DX.

So while verticals are often the simplest path to low angles on multiple bands, a high dipole or beam on a tower can match or exceed that performance. The “best” antenna depends on your space, goals, and which bands you care about most.

How Propagation and Band Choice Change Your Effective Take Off Angle

This is where many hams get tripped up. Even if your antenna has a 10° lobe, that doesn’t mean every path will use it. The ionosphere decides which angles actually work at any given moment.

For example, a 10° shot on 20 meters at sunset might land you Europe easily. But the same angle on 10 meters at a different time of day could overshoot everything useful and never return to the earth. Tools like VOACAP and smartphone apps estimate which angles are likely to work for a path and band based on current conditions.

In practice, this means a simple multiband dipole with several lobes can be surprisingly versatile. As bands open and close, different lobes “light up,” giving you options you may not even realize you had.

Practical Tips to Choose an Effective Take Off Angle

You don’t need formulas—you need results. Here are straightforward ways to nudge your station toward the take off angles that match your goals.

1. For NVIS on 40/80 meters, keep your antenna low—around 0.15–0.25 wavelengths. This encourages the high-angle radiation you need for regional coverage.
2. For DX on 20 meters and above, aim for 0.5 wavelengths or higher for horizontal antennas—or install a well-grounded vertical for naturally low angles.
3. If space is tight, accept compromise. A single wire at mid height often provides a good mix of both NVIS and DX capability across different bands.

Frequently Asked Questions About Take Off Angle

Do I need to know the exact number?

No. Knowing whether your station favors high, medium, or low angles is almost always enough. Modeling and logs give you the practical picture faster than chasing exact degrees.

Can I change my take off angle without rebuilding everything?

Often, yes. Raising or lowering a horizontal antenna shifts its take off angle significantly. Even a change of 10–15 feet can alter your pattern on HF. And remember: the same physical height produces different take off angles on different bands.

Does mode or power change take off angle?

No. Take off angle is purely a function of your antenna and environment. Power and mode affect how loud you are, not the direction your RF prefers to travel. A low-power station with a good angle often beats a high-power station radiating into the wrong part of the sky.