Discover how the 20 Meter End Fed Half Wave Vertical Antenna works, its design, performance, and how it compares to traditional sloper antennas. Whether you’re an amateur radio enthusiast or just exploring antenna designs, this article will walk you through the key features and insights.
Introduction to the 20 Meter End Fed Half Wave Vertical Antenna
If you’re a fan of the End Fed Half Wave (EFHW) antenna, you’ve probably seen the typical horizontal designs that are popular in many ham shacks. But have you ever considered making it vertical? In this article, we’ll explore a 20 Meter End Fed Half Wave Vertical Antenna and how it performs in the real world.
We will cover the design, performance characteristics, and even compare it to other antenna types, so you can determine if this vertical version of the EFHW is right for your setup.
Understanding the Design
The design of the 20-meter End Fed Half Wave Vertical Antenna centers on simplicity and performance. Here’s a breakdown of the key components:
- Driven Element: The antenna features a 10-meter long wire (32.8 feet). This length is specifically chosen to create a half-wave resonant antenna for the 20-meter band.
- 49:1 Unun: A Universal Non-Unity Transformer (Unun) with a 49:1 impedance ratio is used to match the antenna's impedance to your transmitter.
- Counterpoise: Instead of relying on the coaxial cable for counterpoise, this antenna uses a separate counterpoise of 5 meters in length. A proper counterpoise is essential for ensuring a balanced and efficient antenna system.
- Material: The wire is made of copper, a highly conductive material that ensures good performance across the 20-meter band.
The result is a 10-meter tall vertical antenna that’s efficient and easy to deploy. Let’s dive into the performance results.
Performance of the 20 Meter End Fed Half Wave Vertical Antenna
Once the antenna is built, the performance characteristics are tested to see how well it operates. The key parameters to evaluate include the Standing Wave Ratio (SWR), gain, and radiation pattern. Here’s how this vertical antenna performs:
- SWR (Standing Wave Ratio): The antenna shows an impressive SWR of 1.15:1 across the entire 20-meter band. This low SWR means the antenna is resonant and well-tuned for efficient operation.
- Gain: The antenna’s gain is measured at 0.6 dBi, which is typical for vertical antennas. While it might seem low compared to other designs, it’s important to remember that vertical antennas excel at low-angle radiation, which is crucial for long-distance (DX) communication.
The radiation pattern is also key to understanding the antenna’s performance. The vertical design creates a characteristic doughnut-shaped radiation pattern, ideal for general-purpose communications, especially in the 5° takeoff angle, where the antenna achieves a gain of 5.3 dBi.
Comparison with a Traditional Sloper Antenna
How does the 20 Meter End Fed Half Wave Vertical Antenna stack up against a more traditional sloper antenna? Let’s compare the two designs.
- Gain: The vertical antenna has superior gain at the 5° takeoff angle compared to the sloper antenna. This means that the vertical antenna is better suited for long-distance communications, especially at low angles.
- Radiation Pattern: The vertical antenna is omnidirectional, meaning it radiates equally in all directions, providing consistent coverage. On the other hand, the sloper antenna offers some front-to-back directionality, which might be useful in specific cases where you need more targeted coverage.
If you're looking for an antenna with more predictable radiation, the vertical design could be a better choice. However, if you need directional coverage, the sloper might still hold an edge.
Real-World Performance: Testing with Whisper and FT8
To evaluate the real-world performance of the 20 Meter End Fed Half Wave Vertical Antenna, the creator tested it using two popular digital modes: Whisper and FT8. These modes allow operators to transmit low-power signals and assess the performance based on received reports.
During the tests, the antenna performed well despite poor propagation conditions. The Whisper reports showed good signal reception during the day, with results that suggest the antenna is capable of performing effectively under various conditions.
While the 20-meter band performed as expected, the 10-meter band also showed promising results, with a gain of 3.7 dBi at higher frequencies. Although the performance at the 5° angle was lower (8.7 dBi), the antenna still provided reasonable coverage.
Deploying the Antenna
One of the key advantages of the 20 Meter End Fed Half Wave Vertical Antenna is how easy it is to deploy. Unlike many larger antenna designs, this antenna requires minimal space and can be set up in various locations, making it ideal for portable operations or limited spaces in your ham shack.
Whether you’re using it for field operations or setting it up as a permanent antenna, the vertical design is easy to manage and can be quickly installed without requiring extensive tools or adjustments.
Final Thoughts
The 20 Meter End Fed Half Wave Vertical Antenna is a great option for anyone looking to build a simple, efficient vertical antenna for the 20-meter band. With a solid performance in terms of SWR, gain, and radiation pattern, this antenna is perfect for long-distance communication, especially when compared to traditional horizontal designs.
As we’ve seen, the vertical design offers better low-angle radiation, making it a fantastic choice for DX communications. If you’re considering adding a new antenna to your collection or trying out a vertical EFHW for the first time, this design is definitely worth exploring.