2026-11-07
Under the "50Ω cable" label sit two very different constructions: corrugated copper tube and braided cable. Most selection disagreements come from putting the wrong construction in the wrong place.
Three axes of comparison
- Attenuation: at the same diameter, copper tube runs 20–40% lower loss than braid, and the gap widens with frequency. Long runs and high bands favour tube.
- Shielding: the tube's outer conductor is a continuous metal wall, ≥ 90 dB and age-stable; braid delivers 60–90 dB depending on density and can degrade slowly under vibration.
- Bending and installation: braid is flexible and re-bendable, ideal for short equipment jumpers and rack routing; tube needs roughly 10× OD and tolerates only one-time forming.
- Cost and weight: braid is simpler and cheaper; tube costs more per metre but often less per dB — over long runs, price the loss before the cable.
Defaults by scenario
- Base station main feeder (>30 m): corrugated copper tube, 7/8" or 1-5/8".
- Tower-top to antenna (<5 m): 1/2" super-flexible tube or high-shield braid, depending on bends.
- Rack and inter-equipment jumpers: braided or super-flexible for routing and maintenance.
- Tunnel coverage: leaky cable (slotted tube), with braided transitions on branches.
- Test and radar: semi-flexible or high-temperature cable, where phase stability outranks mechanical flexibility.
A common mistake is putting braid on a 100 m trunk — the money saved on cable comes back doubled in coverage metrics. The opposite mistake is all tube inside racks, where installers cannot bend it and end up kinking it.