SIST EN 60712:1999/A1:1999

SLOVENSKI STANDARD
01-april-1999
Helical-scan video-tape cassette system using 19 mm (3/4 in) magnetic tape,
known as U-format - Amendment A1 (IEC 60712:1993/A1:1993)
Helical-scan video-tape cassette system using 19 mm (3/4 in) magnetic tape, known as
U-format
Video-Bandkassettensystem mit Schrägspuraufzeichnung auf Magnetband 19 mm,
bekannt m-als U-Format
Système à cassette à bande vidéo à balayage hélicoïdal utilisant la bande magnétique
de 19 mm (3/4 in), d'appellation format-U
Ta slovenski standard je istoveten z: EN 60712:1994/A1:1994
ICS:
33.160.40 Video sistemi Video systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

NORME CEI
INTERNATIONALE IEC
INTERNATIONAL
STANDARD
AMENDEMENT 1
AMENDMENT 1
1993-06
Amendement 1
Système à cassette à bande vidéo
à balayage hélicoïdal utilisant
la bande magnétique de 19 mm (34 in),
d'appellation format-U
Amendment 1
Helical-scan video-tape cassette system
using 19 mm (34 in) magnetic tape,
known as U-format
© CEI 1993 Droits
de reproduction réservés — Copyright - all rights reserved
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712 Amend. 1 © IEC :1993 - 3 -
FOREWORD
This amendment has been prepared by sub-committee 60B: Video recording, of IEC tech-
nical committee 60: Recording.
The text of this amendment is based on the following documents:
DIS
Report on Voting
60B(CO)122 60B(CO)132
Full information on the voting for the approval of this amendment can be found in the
report on voting indicated in the above table.
Page 11
INTRODUCTION
Replace the last sentence by the following:
The mechanical and electrical specifications for the U-matic H-format and SP-format are
contained in this standard.
Page 13
1 Scope and object
Add the following at the end of the first paragraph:
It contains the definition of parameters for the two-head helical-scan video recording
playback system, using 19 mm (3/4 in) tape cassettes, known as U-matic SP-format
(figures 2b and 2c). The system is suitable for 625/50 PAL and 525/60 NTSC colour tele-
vision systems.
Page 15
Add the following new subclauses:
3.3 Reference tape (SP-format)
Blank tape to be used for reference recordings may be purchased from the manufacturers
listed in annex A. The electromagnetic compatibility parameters and their specifications
should be specified by the manufacturers and controlled accordingly.
The model name is IEC U-matic SP-format reference tape.

712 Amend. 1 ©IEC:1993 – 5 –
Electromagnetic compatibility parameters and their specifications are indicated in
annex A.
3.4 Calibration tape
The calibration tapes which satisfy the following requirements will be available for pur-
chase from the manufacturers producing video tape recorders and players in accordance
with this format specification.
3.4.1 Record locations and dimensions
For the calibration tapes to be used for the purpose of calibrating the mechanical accuracy
of recorder or player in accordance with this format specification, 50 % reduction in the
tolerance shown in table 2, page 63 of IEC 712, should be applied to them in principle.
If necessary, the record locations and dimensions can be specially modified for some
calibration tapes in order to avoid some calibration errors or to help some calibration work.
Calibration signals
3.4.2
Two classes of signals may be recorded on the calibration tapes:
a) A series of conventional test signals:
Video Audio
– Colour bars (75 %) – 1 kHz 0 VU
– Gated sweep – 10 kHz –10 VU
– Pulse and bar – 40 Hz –20 VU
- 1 kHz –20 VU
- 7 kHz –20 VU
– 10 kHz –20 VU
– 15 kHz –20 VU
b) Special test signals developed by each manufacturer for product alignment. These
signals are not universally applicable too the products from all manufacturers and will
not be specified.
Page 21
Add the following new subclause:
Time-code head position for SP-format
5.10
The distance on the tape from the beginning of the 180° scan of video head to the address
head position shall be 48 mm ± 0,1 mm.
Page 27
Add the following new subclause:

712 Amend. 1 ©lEC:1993 - 7 -
11.3
Coercivity (SP tape)
The coercivity shall be approximately 56 x 10 3 A/m - 64 x
103 A/m (700 to 800 oersteds).
Page 27
12 Luminance channel
Add the following description of SP-format before subclause 12.1:
Luminance channel (SP-format)
1 3
-►7►
E F G
_ 9^
IEC 616193
A Low-pass filter 1 Input signal: composite video signal or
B Non-linear pre-emphasis
composite colour signal
C Pre-emphasis
2 Band-limited FM luminance signal
D FM modulator
3 Luminance recording current
E FM high-pass filter
9 Chrominance recording current
F Recording amplifier
G Video head
Page 27
12.2 Recording current
Subclause 12.2.1
Add the following text before the note:
For SP format the recording current shall be the optimum record current at frequencies
shown in the table below over the entire FM carrier bandwidth.
625/50
525/60
6,1 MHz
5,5 MHz
712 Amend. 1 ©IEC:1993 - 9 -
Page 31
Add the following new subclause:
12.3.2 Characteristic frequencies for SP-format
The instantaneous frequencies corresponding to reference video levels shall be as indi-
cated in the table below.
625/50
525/60
Instantaneous
Instantaneous
Reference video level
Tolerance Tolerance
frequency frequency
Sync tip
5,6 MHz (nom.) — 5 MHz (nom.) —
Peak white
7,2 MHz ±0,1 MHz 6,6 MHz ±0,1 MHz
The frequency deviation shall be 1,6 MHz ± 0,1 MHz.
12.4 Pre-emphasis
Add, before 12.4.1, the following sentence:
This also applies to SP-format 525/60.
Page 33
Subclause 12.4.1
Replace the first sentence by the following:
For H-format and SP-format 625/50 the following values apply:
12.5 Recording frequency bandwidth
Add the following new subclause:
12.5.2 Recording frequency bandwidth (SP-format)
For composite colour signals: 30 Hz - 3,3 MHz (-3 dB).
Page 33
Add the following new subclauses and tables:

712 Amend. 1 ©I EC :1993 –11 –
12.6.2 White clipping level after the pre-emphasis (SP-format)
When the sync tip level is 0 % and the white peak level is 100 %, the white clipping level
of the video signal shall lie as shown in the table below:
625/50 525/60
225%to235% 165%to 175%
12.7 Non-linear pre-emphasis (SP-format)
The luminance signal shall receive non-linear pre-emphasis (see diagram below)
...