I was looking for coax to replace the Quarter wave transformer in a commercial VHF Folded Dipole Antenna. Calculations for coax required to match 300 ohms to 50 ohms revealed that a coax with an impedance of approx 120 ohms is required. Z= √300 x 50 equals 122 ohms. RG63 has an impedance of 125 […]
Posts in category Antennas
Have you ever wondered why most of our Amateur Radio equipment is designed for 50 Ohm transmission lines? The following graph was originally produced by two researchers, Lloyd Espenscheid and Herman Affel, working for Bell Labs in 1929. The graph shows the power handling and voltage handling ability of various coax impedances.