1、 STD*SflPTE LSM-ENGL 1998 = 8357403 0003092 227 SMPTE STANDARD for Television Analog Recording - i-in Type B Helical Scan - Basic System Parameters SMPTE 15M-1998 Revision of ANSIISMPTE 15M-1992 1 Scope This standard specifies the basic system parameters, .e., the positions of recording head gaps, t
2、he scan- ning configuration, the axis of rotation of the video head wheel, and the appropriate tape tension for 1 -in type B helical-scan television tape recorders for 525/60 monochrome or NTSC color systems. 2 General specifications 2.1 The dimensions in the metric system are primary. The English e
3、quivalents are derived and may deviate from established conversion practices. 2.2 The video modulation system shall be the FM type. 2.3 The tape speed shall be 245.0 mm/s f 1.2 mm/s (9.646 in/s k 0.047 ids). 2.4 Tests and measurements made on the recorder to check the requirements of this standard s
4、hall be made under the following atmospheric conditions: - temperature - relative humidity 23C f 1 “C (73F k 2F) (50 k 2)% Page 1 of 2 pages - barometric pressure 86 to 106 kPa (860 to 1060 mbar) - conditioning before testing 24 h 3 Video head and scanner parameters 3.1 Two video heads shall be posi
5、tioned 180“ k 30“ apart, , measured from the gap of video head 1 to the gap of video head 2, as shown in figure 1. 3.2 The drum size shall be 50.330 mm +O mm -0.003 mm (1.98150 in +O in -0.00012 in). 3.2.1 The nominal rotational speed of the head wheel shall be 150 r/s. 3.3 The video head tip protru
6、sion shall be 0.060 mm (0.00236 in) max from the outer surface of the drum to the end of the head tip. 3.4 The video head gap shall be 90“ nominal to the plane of rotation of the video head. 3.5 The control head gap shall be located at point Y (see figure 1) which lies on a line which is at 90“ f 2,
7、 measured from diameter F-G which is the centerline through the plate assembly. The users attention is called to the possibility that compliance with this standard may require use of an invention covered by patent rights. By publication of this standard, no position is taken with respect to the vali
8、dity of this claim or of any patent rights in connection therewith. The patent holder has, however, filed a statement of willingness to grant a license under these rights on reasonable and nondiscriminatory terms and conditions to applicants desiring to obtain such a license. Details may be obtained
9、 from the publisher. No representation or warranty is made or implied that this is the only license that may be required to avoid infringement in the use of this standard. Copyright O 1998 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 595 W. Hartsdaie Ave., White Plains, NY 10607 (91 4)
10、761 -1 100 Approved September 1,1998 STD-SMPTE ISM-ENGL 1998 8357901 0003073 lb5 = SMPTE 15M-1998 4 Record tape tension The record tape tension shall be as follows: V Annex A (informative) Bibliography -Tin, tape tension in measured between B and X = 2 N (204 g ) f 10% -Tout, tape tension out measur
11、ed between Y and E = 2.3 N (234 9) +. 10% DIRECTION OF HEAD WHEEL ROTATION A HEAD DIRECTION OF VIDED HEAD 1 IAPE MOTION Figure 1 - Video head ANSIISMPTE 24M-1996, Tetevision Recording - 1 -in Reels ANSI/SMPTE 25M-1995, Video Recording -1 -in Magnetic Recording Tape SMPTE 16M-1998, Television Analog
12、Recording - 1-in Type B Helical Scan - Records SMPTE 17M-1998, Television Analog Recording - 1 -in Type B Helical Scan - Frequency Response and Operat- ing Level SMPTE RP 83-1996, Specifications of Tracking Control Record for 1-in Type B Helical-Scan Television Analog Recording SMPTE RP 84-1996, Reference Carrier Frequencies and Preemphasis Characteristics for 1 -in Type B Helical-Scan Television Analog Recording Page 2 of 2 pages
