Table of Contents
How long is a 15 meter dipole?
The antenna is designed to be fed with 50 or 75 Ohm Coax Cable of most any length with a Balun….Dipole Antenna Calculator.
| 20 Meters | ||
|---|---|---|
| 15 Meters | ||
| 21.000 | 22.29 | 11.14 |
| 21.100 | 22.18 | 11.09 |
| 21.200 | 22.08 | 11.04 |
What is Hpbw of a λ 2 dipole?
The directivity of a half-wave dipole antenna is 1.64 (2.15 dB). The HPBW is 78 degrees.
How do you find Hpbw?
The Half Power Beamwidth (HPBW) is the angular separation in which the magnitude of the radiation pattern decrease by 50% (or -3 dB) from the peak of the main beam. From Figure 2, the pattern decreases to -3 dB at 77.7 and 102.3 degrees. Hence the HPBW is 102.3-77.7 = 24.6 degrees.
How long is a 20m dipole?
Read more about . . . . Dipole Length Calculations.
| Approximate Lengths for HF Ham Band Dipole Antennas | ||
|---|---|---|
| Band (MHz) | Length (Feet) | Length (metres) |
| 14.00 (20 metres) | 34.3 | 10.6 |
| 18.068 | 26.6 | 8.2 |
| 21.00 (15 metres) | 22.8 | 7.04 |
How long is a 20m dipole antenna?
How to calculate the length of a dipole antenna?
The antenna length formulas used in our dipole length calculator are as follows: L = 468 / f. l = L / 2. Where: L – the length of the total dipole antenna in feet (ft); l – the length of the arm of the dipole antenna in feet (ft); and; f – the desired frequency. We also used the simple wavelength formula: Wavelength = c / f. Where:
What is the frequency of a 20 meter vertical dipole?
For the 20 meter vertical dipole, I selected a frequency of 14.200 MHz. Using the general formula 234/f (MHz)=L (ft) and allowing for a few inches of overlap, I cut each dipole element to a length of 16.6 feet (5.06 meters). The top half of the 20 meter dipole was attached and soldered to the + terminal of the Budwig connector.
Does the vertical dipole antenna work well?
The vertical dipole seems to work as well as my 40-10 meter inverted vee fed with 450-ohm ladder line. Of course, the 20 meter antenna is strictly a one-band affair, while the inverted vee can be used on other bands from 40 through 10 meters.
What size stake do I need for a vertical dipole?
The stake should be at least 5-feet (1.52 meters) long to provide enough support for the flexible mast. Nylon ties and vinyl electrical tape to secure the vertical elements to the mast. The antenna was built on the ground and then hoisted over the support stake. For the 20 meter vertical dipole, I selected a frequency of 14.200 MHz.