IEC 61118-1993 PDF

Full title and description

Helical-scan video tape cassette system using 12,65 mm (0,5 in) magnetic tape - Type M2. Defines the mechanical dimensions, tape and recorder characteristics, recording formats and audio modes necessary to ensure interchangeability of recorded cassettes for 525 line–60 field and 625 line–50 field systems.

Abstract

IEC 61118:1993 specifies the Type M2 helical‑scan video tape cassette format (12.65 mm / 0.5 in). The standard covers cassette external dimensions (large and small types), datum and locator features, mechanical tolerances for cassette and recorder interfaces, drum/scan geometry, tape characteristics (width, thickness, coercivity), video track layout and timing, audio recording modes (common audio, optional FM, and PCM with limited interchangeability), calibration/reference tape requirements and standard test/environmental conditions for measurement.

General information

• Status: Published / Valid (base international standard).
• Publication date: 30 August 1993 (first edition).
• Publisher: International Electrotechnical Commission (IEC).
• ICS / categories: 33.160.40 (Video systems).
• Edition / version: Edition 1.0 (1993).
• Number of pages: 169 (IEC base publication pagination).

Scope

The standard is applicable to magnetic video recording using 12,65 mm (0.5 in) tape cassettes on helical‑scan recorders and defines the M2 format. It specifies dimensions and mechanical interfaces to ensure interchangeability of recorded cassettes and gives requirements relevant to both NTSC-like 525 line/60 field and PAL-like 625 line/50 field systems. It also specifies audio recording modes, calibration tapes and environmental/test conditions for reproducible verification.

Key topics and requirements

• Cassette form factors and datum system (two sizes: large 106 × 188 × 25 mm and small 87 × 130 × 25 mm) with specified window, label and identification features to permit reliable loading and interchangeability.
• Mechanical tolerances for lid forces, reel brake release, tape path and reel geometry to ensure consistent loading and recording alignment.
• Recorder/drum geometry and helix/track angle definitions (including precise helix angle and pole tip geometry) to control track placement and head‑to‑tape contact.
• Tape physical and magnetic properties (width, thickness, coercivity ranges, leader/trailer provisions and magnetization level/rise time requirements).
• Video recording characteristics: luminance/chrominance allocation, track locations and timing tolerances, azimuth/gap specifications, and Y–C timing requirements.
• Audio modes: common analog audio, optional FM audio, and PCM audio mode (PCM interchangeability limited and noted in the standard).
• Calibration and reference tape definitions and recommended test signals and environmental/test conditions (temperature, humidity, conditioning times) for repeatable measurements.

Typical use and users

Engineers and manufacturers of helical‑scan video tape recorders and players, tape and cassette producers, test laboratories and archival/media preservation professionals use this standard to design equipment and media that are mechanically and electrically interoperable with the M2 cassette format. It is also used by standards bodies and national committees when adopting equivalent regional standards.

Related standards

EN 61118:1993 (European adoption), BS EN 61118:1994 and various national adoptions (UNE‑EN 61118, NBN, DIN EN, etc.) are direct regional equivalents/adoptions of IEC 61118:1993. The standard cross‑references related magnetic‑tape and recording documents (examples include IEC 94‑1 and IEC 461 referenced within the standard).

Keywords

Helical‑scan, video tape cassette, Type M2, 12.65 mm, 0.5 in, magnetic tape, cassette dimensions, interchangeability, drum geometry, track angle, PCM audio, calibration tape, IEC 61118.

FAQ

Q: What is this standard?

A: IEC 61118:1993 is an international standard that defines the Type M2 helical‑scan video tape cassette system using 12,65 mm (0.5 in) magnetic tape, covering mechanical, tape and recording characteristics to ensure interchangeability.

Q: What does it cover?

A: It covers cassette dimensions and datum features, mechanical tolerances, recorder/drum geometry and helix/track definitions, tape magnetic/physical properties, video and audio recording characteristics (including PCM), calibration/reference tape requirements and standard test/environmental conditions.

Q: Who typically uses it?

A: Manufacturers of video cassette recorders and tapes, test laboratories, product designers, archivists and standards bodies adopting regional equivalents. It is used where mechanical and recording interchangeability with M2 cassettes is required.

Q: Is it current or superseded?

A: IEC 61118:1993 is the base publication from 30 August 1993 and has been adopted regionally (EN 61118:1993 / BS EN 61118:1994, UNE‑EN 61118, etc.). Available records list it as the 1993 base publication and as adopted in later regional editions; it is treated as the normative IEC publication for the M2 format. Users should check national bodies for any later amendments or withdrawal notices in their jurisdiction.

Q: Is it part of a series?

A: It is part of the IEC/TC 100 family of video/recording standards and references other relevant IEC documents for magnetic tape recording and test methods; regional standards bodies have produced EN/BS/UNE adoptions based on it.

Q: What are the key keywords?

A: Helical‑scan, video cassette, Type M2, 12.65 mm, magnetic tape, interchangeability, drum geometry, PCM, calibration tape.