Copyright Goodheart-Willcox Co., Inc. 59 Chapter 2 Network Media—Copper-Core Cable Corrugated roof Raised floor Plenum area Concrete slab Steel joists Plenum area Ceiling tile Figure 2-12 The plenum area of a building is located above a drop ceiling and under a raised floor. Goodheart-Willcox Publisher Th e core of a coaxial cable can be either solid or stranded. A solid core is stiff er and more diffi cult to work with than a stranded core. However, neither is as fl exi- ble as twisted pair and fi ber-optic cable. Another interesting fact is a stranded core has the ability to carry more electrical energy (current) than a solid core of equal dimensions. Stranded-core coaxial cable, therefore, can contribute to a better quality of signal than solid-core coaxial cable. Many times, the most important factor in determining which cable type to use is cost. Solid copper-core coaxial cable is less expensive than stranded copper-core coaxial cable. Th is is true for all copper cable types manufactured. Th e exact type Braided copper shield Foil shield Dielectric Insulating outer jacket Copper core Figure 2-13 Coaxial cable layers. Goodheart-Willcox Publisher