- Found it. This comes from "Engineering and Operations in the Bell System."
This particular excerpt is from a section on microwave radio.
"The radio transmitters and receivers are always located as close as
possible to the antenna tower to minimize losses in the antenna waveguide
system. At a multiplex location, the FM terminals similarly are located in
close proximity to the radio equipment to minimize IF cable losses. In many
cases, this leaves the FM terminals at a considerable distance from the
multiplex terminals (up to 1000 feet typically, but up to a few miles in
some instances). A wire-line entrance link (WLEL) is used to connect the
multiplex terminals to the FM terminals. The WLEL is a coaxial cable
facility that, depending on its length, may or may not be repeatered. The
link includes baseband amplifiers and cable equalizers to compensate for the
loss and attenuation shape of the cable."