1. What is an End Fed Half Wave Antenna Calculator?

Definition: This calculator estimates the length of an end-fed half-wave antenna based on the desired frequency and speed of light.

Purpose: It helps radio enthusiasts and engineers determine the proper antenna length for optimal signal transmission and reception.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Length \) — Antenna length (meters)
• \( c \) — Speed of light (3×10⁸ m/s)
• \( f \) — Frequency (Hz)

Explanation: The speed of light is divided by frequency to get wavelength, then halved for a half-wave antenna.

3. Importance of Antenna Length Calculation

Details: Proper antenna length ensures efficient energy radiation and reception, matching the desired frequency for optimal performance.

4. Using the Calculator

Tips: Enter the desired frequency in Hz and speed of light (default 3×10⁸ m/s). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why divide by 2 in the formula?
A: The division by 2 calculates the half-wave length, which is a common and efficient antenna configuration.

Q2: What's a typical frequency range?
A: Common amateur radio frequencies range from 3.5 MHz to 440 MHz, but the calculator works for any frequency.

Q3: When would I change the speed of light value?
A: Normally you wouldn't, but you might adjust for different propagation mediums (e.g., in coax cable).

Q4: Does this account for velocity factor?
A: No, this calculates free-space length. For practical antennas, multiply by 0.95-0.97 for wire antennas.

Q5: Is this for dipole or end-fed antennas?
A: This calculates the half-wave length which can be used for both, but the feed point impedance differs.