75 Ohm Coax

75 Ohm Coax for Amateur Radio

Advantages and Disadvantages
Advantages
  • Lower loss than 50Ω cable of comparable diameter
  • Often a better impedance match to common wire antennas (dipoles, loops)
  • Significantly cheaper than equivalent 50Ω cable
  • Excellent shielding available (quad-shield RG-6)
  • Works fine with an antenna tuner
Disadvantages
  • Higher SWR on antennas with naturally low feedpoint impedance (Yagis, verticals with horizontal radials)
  • F connectors require adapters for amateur radio equipment
  • SWR at the radio may vary with feedline length, since the line Z₀ differs from what the radio expects
  • Not recommended at legal limit power with high SWR (voltage stress)