Ham Radio Antenna Design Notes

Math

492 / Freq in MHz

Calculate length for an inverted V antenna.

1005 / MHz

Calculate length for a full wave loop antenna.

Talking Points of Experience

Loading coil to simulate length, but inefficient and generates heat, doesn't handle high power well.

DC grounded antennas are ideal: prevents static build up on antenna

Precision in element length becomes more significant at higher frequency

Understand how capacity hats impact resonance

Impedance Dipole vs Inverted V

A dipole in free space should have about 72 ohms of input impedance. As you move the poles down to form and inverted V the impedance lowers.

A folded dipole needs a 4:1 balun