RS-170 (Electrical Performance Standards - Monochrome Television Studio Facilities)

Originally issued in November of 1953, this document is the EIA broadcast studio standard for the NTSC black and white video format. It consists of definitions, minimum standards, and methods of measuring important standards for the 525 line interlaced TV system. It describes a 2:1 interlaced signal where a total number of lines occur over the period of a 30th of a second. The horizontal frequency is 15,750 Hz, which is derived from 525 lines per complete picture x 30 pictures per second. The vertical frequency is 60 Hz because of the 2:1 interlace. The video signal is defined as 1.4 volts peak-to-peak. The video bandwidth extends from 30 Hz to about 4.18 MHz. The upper frequency limit is determined by RF transmission requirements of a video signal.