TC 9-64 _________________________________________________________________________
Two-wire open lines are parallel lines and have uses such as power lines,
rural telephone lines, and telegraph lines. This type of line has high radiation
losses and is subject to noise pickup.
Figure 3-Sum 1. Two-Wire Open Line
The two-wire ribbon (twin lead) has parallel lines and is most often used to
Figure 3-Sum 2. Two-Wire Ribbon Type Line
A twisted pair consists of two insulated wires twisted together. This line has
high insulation loss.
Figure 3-Sum 3. Twisted Pair