If you don’t have two tall trees for a dipole, don’t worry! You can go vertical. Vertical antennas are famous for their low angle of radiation, which is perfect for reaching distant countries (DX).
1. What is a Ground Plane (GP)?
A Ground Plane antenna is essentially “half a dipole” placed vertically. Since it’s missing the other half, we create an “artificial ground” using wires called radials.
- The Radiator: The vertical element (the signal).
- The Radials: The horizontal or sloping wires (the mirror).
2. DIY: A 10-Meter Ground Plane
The 10-meter band (28 MHz) is perfect for DIY because the antenna is small (only about 2.5 meters tall).
Materials needed:
- One SO-239 connector (chassis mount).
- Stiff wire (aluminum, copper, or even a wire on a insulated rod).
- 4 wires for radials.
How to build it:
- The Vertical Whip: Cut a wire to 2.6 meters and solder it to the center pin of the SO-239.
- The Radials: Connect 4 wires (each 2.7 meters long) to the four holes of the SO-239 flange.
- The Secret Angle: Tilt the radials downwards at about 45 degrees. This trick brings the impedance close to 50 Ohms, so you get a perfect SWR!
3. Magic on 10 Meters: Few Watts, Thousands of Miles
The 10-meter band is magical. When the Solar Cycle is at its peak (like now!), the ionosphere becomes a perfect mirror.
- Low Power, High Fun: You don’t need 100 Watts. With just 5 or 10 Watts (QRP) and this simple vertical antenna, you can easily talk from Europe to South America or the USA.
- Compact size: Because it’s small, you can mount it on a simple pole or even take it to a park!
- Check your signal: Want to see where your few watts are going? Use the Reverse Beacon Network (RBN) or check the online Grabbers (like the ones on my site!). These systems will show you in real-time if your signal is being heard across the ocean.
4. Deepening and Technical Resources
- M0UKD – 1:4 Wave Ground Plane Calculator: A great tool to calculate the exact length for any frequency.
- ARRL – Vertical Antenna Basics: For those who want to learn more about the importance of the grounding system.
- Reverse Beacon Network: To see who is receiving your CW or Digital signal.
Pro Tip: If you mount your GP at ground level, you need many radials on the grass. If you mount it high (on a roof or mast), just 3 or 4 resonant radials are enough to work the world!
Coming Soon: We have seen the Ground Plane “in the air”, but what if you want to mount your antenna directly on the lawn? In a future post, we will talk about Ground-Mounted Verticals and Buried Radials – the secret for a stealth and efficient setup!
Next Step: Ready for something different? In the next pill, we will talk about the Magnetic Loop – the small antenna that defies physics!
