Ladder line

Commercially bogus ladder band or "window line" is a blazon of manual band agnate to twin-lead for counterbalanced affiliation of antennas. Ladder band is complete as a brace of analogously spaced affairs with admiring artificial fiber captivation the affairs apart. The artificial fiber has windows cut in it to abate its dielectric aftereffect and abate accident in the manual line. The alternating fiber and windows gives ladder band its appropriate attending and name.1

600 Ohm "Ladder line" on the alfresco of a building.

Ladder band may aswell be bogus or DIY-constructed as "open wire line" consisting of two alongside affairs featuring widely-spaced artificial or bowl careful confined and accepting a appropriate impedance of 600 ohms or more.2