The common types are coaxial cable, twin-lead, twisted-pair, wave-guide, and strip-line (PC etch). Coaxial cable is recommended for all TV systems. Although lamp cord can be used for transmission line, it has some problems. Twin-lead (ribbon cable) used to be common for TV antennas. It has its advantages. But due to its unpredictability when positioned near metal or dielectric objects, it has fallen out of favor. (Such objects, even if not touching the cable, cause a portion of the signal to bounce, return to the antenna, and get retransmitted.)
All high frequency transmission lines have a property called characteristic impedance. Twin-lead is usually 300 ohms, while coaxial cable for TVs should always be 75 ohms. (50 ohm coaxial cable is also common. Avoid that cable.) Although rated in ohms, this has nothing to do with resistance. A resistor converts electric energy into heat. The
Transmission lines
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