Software available for downloading from public networks and bulletin board systems, usually at little cost.
Note: At the end of a trial period, users are asked to pay the software developer a small amount for use of the software. [After Bahorsky]

The informal, subjective evaluation of detail in the clarity or resolution seen in an image.
Note: Often sharpness and resolution are assumed to be directly related, because images possessed of greater sharpness are assumed to have greater resolution. An increase in subjective sharpness is usually reported when objects are more clearly delineated from each other and from background having hard,… (Read More →)

Super Head End

Of a communications or power cable, the outer covering or coverings of tough material, often plastic, that is resistant to environmental hazards such as abrasion, liquid intrusion, solar radiation, etc. , and is used to protect cable component(s) such as optical fibers or metallic conductors that transport the signal or power.
Note: There may be more than one sheath surrounding… (Read More →)

The actual length of cable in route kilometers. [47 CFR Pt.36-A]

The actual length of cable in route miles. [47CFR]

In a computer environment, an operating system command interpreter, i.e., a software utility that reads an input specifying an operation, and that may perform, direct, or control the specified operation.
Note 1: For example, a shell may permit a user to switch among application programs without terminating any of them.
Note 2: A shell may take its input from either… (Read More →)

Abbreviation for super high frequency. See electromagnetic spectrum.

1. A housing, screen, sheath, or cover that substantially reduces the coupling of electric, magnetic, or electromagnetic fields into or out of circuits or transmission lines.
2. A protective cover that prevents the accidental contact of objects or persons with parts or components operating at hazardous voltage levels.

[A] room or container designed to attenuate electromagnetic radiation. [INFOSEC-99]