Type C helical video tape recorders

Includes magnetic video recording and/or reproduction using  25, 4 mm tape. Defines the electrical and mechanical  characteristics of equipment which will provide for  interchangeability of recordings. The requirements given are  related to 525 line/60 field and/or 625 line/50 field systems.  Describes formats, environment, tapes and spools, transport  geometry parameters and the basic system, dimensions and  location of records and electrical parameters.

Videobandgeräte mit Schrägspuraufzeichnung Typ C

Magnétoscopes à enregistrement hélicoïdal de type C

Définit les caractéristiques électriques et mécaniques des équipements qui permettront l'interchangeabilité des enregistrements. Les exigences indiquées sont relatives aux systèmes 525 lignes-60 trames et/ou 625 lignes-50 trames. S'applique àl'enregistrement et/ou à la reproduction magnétique vidéo utilisant la bande 25,4 mm (1 in) sur les magnétoscopes à défilement hélicoïdal de type C convenant aux applications de radiodiffusion.

Videorekorderji tipa C

General Information

Status
Published
Publication Date
31-Dec-2006
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
01-Jan-2007
Due Date
01-Jan-2007
Completion Date
01-Jan-2007

RELATIONS

Buy Standard

Standardization document
SIST HD 573 S1:2007
English language
30 pages
sale 10% off
Preview
sale 10% off
Preview

e-Library read for
1 day

Standards Content (sample)

6/29(16., 6,67+'6
67$1'$5'
MDQXDU
9LGHRUHNRUGHUMLWLSD&
LVWRYHWHQ+'6
7\SH&KHOLFDOYLGHRWDSHUHFRUGHUV
,&6 5HIHUHQþQDãWHYLOND

6,67+'6 HQ
!"#$%&’( )&!*+,%- .
---------------------- Page: 1 ----------------------
NORME
CEI
INTERNATIONALE
IEC
60558
INTERNATIONAL
Première édition
STAN DARD
First edition
1982-01
Magnétoscopes
à enregistrement helicoïdal
de type C
Type C helical video tape recorders
© IEC 1982 Droits de reproduction réservés —
Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni
No part of this publication may be reproduced or utilized in
utilisée sous quelque forme que ce soit et par aucun
any form or by any means, electronic or mechanical,
procédé, électronique ou mécanique, y compris la photo-
including photocopying and microfilm, without permission in
copie et les microfilms, sans l'accord écrit de l'éditeur.
writing from the publisher.
International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: +41 22 919 0300 e-mail: inmail@iec.ch IEC web site http: //www.iec.ch
CODE PRIX
Commission Electrotechnique Internationale
PRICE CODE
International Electrotechnical Commission
IEC
Me>tsuyHapoaHaa 3neKrporexHHVecMaa KoMt7ccIa
Pour prix, voir catalogue en vigueur
• •
For price, see current catalogue
---------------------- Page: 2 ----------------------
- 3 -
558 © I EC 1982
CONTENTS
Page
FOREWORD 5
PREFACE 5
Clause
1. Scope 7
2. Object 7
7 3. Format description
4. Environment 7
5. Tapes and spools 7
5.1 Dimensions of magnetic tape for television
5.2 Spools 9
5.3 Magnetic tape properties
6. Transport geometry parameters and description of the basic system
6.1 Definitions of terms
13
6.2 Video and sync record system
6.3 Scanner pole tips 13
6.4 Scanner guides 15
15
6.5 Drum diameter and tape tension
15
7. Dimensions and location of records
7.1 Test environment
7.2 Tape speed
17 7.3 Record locations and dimensions
7.4 Video record straightness
7.5 Relative positions of recorded signals
17
7.6 Gap azimuth
8. Electrical parameters
23
8.1 Modulation system
23
8.2 Signal processing
8.3 Characteristic frequencies
25
8.4 Record head current
27
8.5 Recording of the audio tracks
27
8.6 Tracking control record
30
FIGURES
39
APPENDIX A - Transmission characteristics of the signal chain
---------------------- Page: 3 ----------------------
558 © I E C 1982 - 5 -
INTERNATIONAL ELECTROTECHNICAL COMMISSION
TYPE C HELICAL VIDEO TAPE RECORDERS
FOREWORD

1) The formal decisions or agreements of the I EC on technical matters, prepared by the Technical Committees on which all

the National Committees having a special interest therein are represented, express, as nearly as possible, an international

consensus of opinion on the subjects dealt with.

2) They have the form of recommendations for international use and they are accepted by the National Committees in that

sense.

In order to promote international unification, the I EC expresses the wish that all National Committees should adopt the

text of the I EC recommendation for their national rules in so far as national conditions will permit. Any divergence

between the I EC recommendation and the corresponding national rules should, as far as possible, be clearly indicated in

the latter.
PREFACE

This standard has been prepared by Sub-Committee 60B: Video Recording, of I EC Technical

Committee No. 60: Recording.

Drafts were discussed at the meeting held in Palo Alto in 1979. As a result of this meeting, a draft,

Document 60B(Central Office)40, was submitted to the National Committees for approval under

the Six Months' Rule in March 1980.

The National Committees of the following countries voted explicitly in favour of publication:

Austria Netherlands
Belgium New Zealand
Canada Poland
Denmark Romania
Egypt South Africa (Republic of)
France Spain
Germany Turkey
Israel Union of Soviet
Italy Socialist Republics
Japan United States of America
Korea (Republic of)
Other IEC publications quoted in this standard:
Publications Nos. 94: Magnetic Tape Sound Recording and Reproducing Systems.
347: Transverse Track Recorders.
461: Time and Control Code for Video Tape Recordings.
503: Spools for 1 in (25.4 mm) Video Magnetic Tape.
---------------------- Page: 4 ----------------------
558 © I EC 1982 - 7 -
TYPE C HELICAL VIDEO TAPE RECORDERS
1. Scope

This standard applies to magnetic video recording and/or reproduction using 25.4 mm

(1 in) tape on type C helical video tape recorders suitable for broadcast applications.

Object

The object of this standard is to define the electrical and mechanical characteristics of

equipment which will provide for interchangeability of recordings. The requirements given

are related to 525 line-60 field and/or 625 line-50field systems.
3. Format description

Two video recording heads are used, one for the active period of the field and a part of the

vertical interval and one for the remainder of the ve rtical interval. Use of the latter head is

optional.
4. Environment

Tests and measurements made on the recorder to check the requirements of this standard

shall be carried out under the following conditions:
Temperature (drum diameter) 23 ± 0.5°C
Temperature (all other tests) 23 ± 1 °C
Relative humidity 48 Vo 52%
Barometric pressure 86 kPa to 106 kPa
24 h
Conditioning before testing:
5. Tapes and spools
5.1 Dimensions of magnetic tape for television

The magnetic tape used for television recording shall conform to the following dimensions:

Millimetres Inches
25.350 0.9980 ±oôôi
Width
±ô.ozs
Maximum overall thickness 0.0012
0.030
Maximum longitudinal curvature 1.3 in 1 m 0.051 in 39.4
Note. - The curvature shall be measured by standard IEC procedures as
shown in Figure 1, page 30.
---------------------- Page: 5 ----------------------
- 9 -
558 © I EC 1982
5.2 Spools

5.2.1 Spools shall conform to the requirements of ISO Standard 1860. The preferred spool

diameters are listed in I EC Publication 503: Spools for 1 in (25.4 mm) Video Magnetic Tape.

If a friction ring is used, dimension C shall be:
115 ±; mm (4.528 in)
±ô29

The friction ring shall not impair spool performance or long-term storage of tape. (See

Tables I and II and Figure 2, page 30.)
TABLE I
Spool dimensions
Dimensions Millimetres Inches Degrees
76.2 +ôâ 3.000
±0.ôoô
C 114.0± 4.500±0.010
0.0
D 82.5 3.250 0.002
0.0
5.60 0.219
±0.000
±ô.ôô
120.0 ± 0.1
H 0.65 max. 0.025 max.
2.5 max. 0.098 max.
K 91.5 min. 3.600 min.
L 153 min. 6.000 min.
1.212 ± 0.003
M 30.8 ± 0.1
TABLE II
Dimension B
Inches
Millimetres
203.0 8.000 0.010
0.0
229.0 +05 9.000 ± 0.010
2480 .
9.750
± 0.0
267.0 ± âô 10.500 ± 0.010
---------------------- Page: 6 ----------------------
558 © I E C 1982
TABLE III
Approximate spool capacities
Approximate capacity Approximate maximum
Diameter of spool playing time
based upon nominal
thickness of 0.030 mm (min)
625 line- 525 line-
Millimetres Inches Feet 50 field 60 field
Metres
system system
8 45
203 650 2100 44
229 9 900 62
3 000 61
248 9.75 1125 3 700 78 77
267 10.5 1400 4 600 97 95

5.2.2 A minimum distance of 3 mm (0.12 in) from the tape to the spool periphery shall be allowed.

Approximate spool capacities are given in Table III.
5.3 Magnetic tape properties
5.3.1 The magnetic coating shall be longitudinally oriented.
5.3.2 The coercivity shall be more then 30 x 10' A/m.
6. Transport geometry parameters and description of the basic system
of terms
6.1 Definitions

The following definitions of terms are given to assist in the correct understanding of this

part of the standard.
6.1.1
Scanner

The mechanical assembly comprising a drum, rotating pole tips and tape-guiding elements.

It is used to record and reproduce video tape recordings.
6.1.2 Drum

The circular cylinder around which tape is at least partially wrapped in order to form the

head-to-tape interface of a video tape recording system.
6.1.3 Upper drum

That part of the drum in a helical-scan video recording system which does not contact the

reference edge of the tape in this format.
6.1.4 Lower drum

That part of the drum in a helical-scan video recording system which contacts the reference

edge of the tape and usually contains tape-guiding elements.
---------------------- Page: 7 ----------------------
558 © I EC 1982 - 13 -
6.1.5 Effective drum diameter

The value of drum diameter which when used in theoretical calculations will correspond to

the actual video record produced in a helical-scan video tape recording system. The effective

value is equal to or greater than the actual drum diameter.
6.1.6
Helix angle

The angle formed between the path of the rotating pole tips and the tape-reference-edge

guiding system on the scanner of a helical-scan video tape recording system.
6.1.7 Track angle

The angle of the recorded video track with respect to the reference edge of the tape in a

helical video tape recording.
6.1.8 Centre span tension

The calculated value of tape tension at a point midway between tape entrance and exit

guides of the scanner in a video tape recording system.
6.2 Video and sync record system

6.2.1 Exactly one field of video shall be recorded during each scanner revolution. The video

record shall contain all active picture lines and sufficient vertical-sync information for play-

back synchronization. Information not contained in the video record is defined as the ver-

tical-interval drop-out.

6.2.2 Recording of the missing vertical interval information shall be optional. However, no other

information shall be recorded in the allotted tape area for 525-60 systems. A longitudinal

audio track (audio 4) may be recorded in the area in lieu of the missing vertical information

for 625-50 systems.

6.2.3 The optional record of the vertical interval information shall contain a number of horizontal

TV lines during the vertical interval, those of the vertical interval including drop-out and suf-

ficient overlap of information for playback switching.
6.3 Scanner pole tips

6.3.1 There shall be six circumferential pole tip locations as shown in Figure 3, page 31 (top view).

When an operational pole tip is not required, a suitable inoperative tip shall be placed in the

same location.

Note. - The inoperative tips have mechanical characteristics similar to those of the pole tips but without any elec-

trical function. Their main function is to cause the tape to assume the same deformation as that produced

when a pole tip is used in the same place.

6.3.2 Each tip projection shall be 0.06 ± 0.03 mm (0.0024 ± 0.0012 in) measured from the outer

surface of the upper drum to the end of the pole tip.

6.3.3 The axial distance between each video-head pole tip and its associated sync-head pole tip

shall be as shown in Figure 3 (side view).
---------------------- Page: 8 ----------------------
558 © I EC 1982 - 15 -
6.4 Scanner guides

6.4.1 Location of the tape entrance and exit guides shall provide a tape-wrap angle such that the

video record vertical-interval drop-out is 10.00 ± 0.25 horizontal lines for 525-60 systems or

11.90 ± 0.30 lines in 625-50 systems due to loss of head-to-tape contact, with no electronic

switching of the recording signal. Start and end of the vertical-interval drop-out shall be

measured at the half-amplitude points of the r.f. signal envelope produced by the video head.

The measurements shall be made with a tip projection of 0.06 mm (0.0024 in).

6.4.2 The helix angle formed by the scanner and the associated tape guides shall be

2° 35' 29" ± 2".
6.5 Drum diameter and tape tension

Effective drum diameter, tape tension, helix angle, and tape speed completely determine

the video-record track angle. Different methods of design and/or minor variations in drum

diameter and tape tension shall produce equivalent recordings for interchange purposes.

Values and operating conditions specified in this sub-clause will produce the reference value

of track angle.

6.5.1 The actual upper drum diameter shall be 134.620 ±" ô mm (5.300 00 ± "0" in).

ô 000
0.000
The actual lower drum diameter shall be 134.580 ± ô00s mm (5.298 43 + 00 in).
6.5.2 The upper drum shall rotate in synchronism with the video tips.
6.5.3 The centre-span tape tension shall be 1.7 ± 0.3 N.
7. Dimensions and location of records

This part of the standard specifies the dimensions and locations of recorded video, audio

and tracking control records.
7.1 Test environment

7.1.1 In addition to the general test environmental requirements of Clause 4, the following addi-

tional conditions shall be met in order to meet the requirements of Clause 7:
Tape tension: 1.7 ± 0.3 N
7.1.2 Conditioning before recording and testing
Environmental: stabilized at the measurement conditions
Tape tension: wound on a reel at 0.5 N to 3.0 N

7.1.3 The reference edge of the tape for dimensions in this standard shall be the lower edge as

shown in Figure 4, page 32. The magnetic coating of the tape faces the observer in all figures.

---------------------- Page: 9 ----------------------
558 © I EC - 17 -
1982
7.2 Tape speed
7.2.1

The tape speed shall be 244.0 ± 0.5 mm/s (9.606 ± 0.020 in/s) for 525-60 systems.

7.2.2 The tape speed shall be 239.8 ± 0.5 mm/s (9.441 ± 0.020 in/s) for 625-50
systems.
7.3 Record locations and dimensions

7.3.1 Record locations and dimensions shall be as specified in Figure 4, page 32, and Table IV.

7.3.2 Dimensions P, Q, R and
O are for reference purposes only. The parameters given in Clause 6

and Figure 3, page 31, and the tape speed completely determine these values and their toler-

ances. The nominal values given are based on tensioned tape; hence, direct measurement

without tension shall take into account the elasticity of the tape.
7.4 Video record straightness

The edge of the video record shall be contained within two parallel straight lines 0.030 mm

(0.00118 in) apart.
7.5 Relative positions of recorded signals
7.5.1

Video, sync, tracking control, and audio signals with information intended to be time

coincident shall be positioned as shown in Figures 5A and 5B,
pages 33 and 34.
7.5.2

The start of the video record is that location on the video record which would be produced

by scanner and guide locations with no electronic switching of the recording signal (dimen-

sion
G).

7.5.3 The vertical-interval drop-out timing with respect to a television frame is determined by

dimension CC measured from the reference tape edge to the leading edge of line 16 sync at the

video track centre line.

7.5.4 The start and end of the sync record shall be produced by electronic switching of the

recording signal due to geometric constraints (dimensions C and D).
Positioning of the

leading edge of line 16 sync, at the sync track centreline, with respect to the reference tape

edge shall be as per dimension EE.
7.6 Gap azimuth
7.6.1

The azimuth of all head gaps used to produce longitudinal track records shall be perpendi-

cular to the direction of relative head-to-tape motion.

7.6.2 The azimuth of the video and sync gaps shall be perpendicular to the direction of head

motion.
---------------------- Page: 10 ----------------------
558 © IEC 1982 -19-
TABLE
Record locations and dimensions
Millimetres Inches
Description
Symbol
Min. Max. Min. Max.
0.200 0.00000 0.00787
A Audio 3 lower edge 0.000
B Audio 3 upper edge 0.775 1.025 0.03051 0.04035
C Sync track lower edge
1.445
525-60 1.385 0.05453 0.05689
625-50 1.370 1.430 0.05394 0.05630
D Sync track upper edge
525-60 2.680 2.740 0.10551 0.10787
625-50 2.696 2.756 0.10614 0.10850
E Control track lower edge 2.870 3.130 0.11299 0.12323
F Control track upper edge 3.430 3.770 0.13504 0.14843
G Video track lower edge
3.860 0.15433
525-60 3.920 0.15197
625-50 3.845 3.905 0.15138 0.15374
H Video track upper edge
525-60 22.355 22.475 0.88012 0.88484
625-50 22.370 22.490
0.88071 0.88543
J Audio I lower edge 22.700 22.900 0.89370 0.90157
K Audio I upper edge 23.475 23.725 0.92421 0.93406
L Audio 2 lower edge 24.275 24.525 0.95571 0.96555
M Audio 2 upper edge 25.100 25.300 0.98819 0.99606
Video and sync track width
525-60 0.125 0.135 0.00492 0.00531
625-50 0.165
0.155 0.00610 0.00650
P Video offset
525-60 4.067 (2.5 H) nom.
0.16012
625-50 4.791 (3.5 H) nom. 0.18862
Video track pitch
525-60 0.1823 nom. 0.007177
625-50
0.2144 nom. 0.008441
---------------------- Page: 11 ----------------------
558 © IEC 1982
-21-
TABLE IV
(continued)
Millimetres
Inches
Symbol Description
Min. Max. Min. Max.
R Video track length
525-60
410.764 (252.5 H) nom. 16.17181
625-50 411.467 (300.6 H) nom.
16.19949
Control track and audio heads
distance
525-60
101.60 102.40 4.0000 4.0315
625-50 101.80 102.60
4.0079 4.0394
Drop-out-to reference line
(odd field)
525-60
1.625 (1.0 H) nom. 0.063976 nom.
625-50 1.779 (1.30 H) nom.
0.070039 nom.
Drop-out-to-reference line
(even field)
525-60
2.440 (1.5 H) nom. 0.09606 nom.
625-50 2.464 (1.8 H) nom.
0.09701 nom.
Sync track length
525-60 25.620 (15.75 H) 26.420 (16.25 H) 1.0087
1.0402
625-50
25.665 (18.75 H) 26.350 (19.25 H) 1.0104 1.0374
W Start of record-
to-reference line
(odd synchronization field)
525-60
22.765 (14 H) nom. 0.89626 nom.
625-50 22.928 (16.75 H) nom.
0.90268 nom.
Start of record-
to-reference line
(even synchronization field)
525-60 23.575 (14.5 H) nom.
0.92815 nom.
625-50 23.612 (17.25 H) nom.
0.92961 nom.
Y Vertical video synchronization head offset
1.529 nom. 0.06020 nom.
Z Horizontal video/synchronization head
offset 35.350 nom.
1.39173 nom.
B Track angle
525-60
2°34'00" nom.
625-50 2°33'44.4" nom.
AA Audio 4 lower* edge 1.500 1.700
0.05906 0.06693
BB Audio 4 upper* edge
2.275 2.525 0.08957
0.09941
* Audio 4 is optional track for 625-50 systems only.
---------------------- Page: 12 ----------------------
I EC 1982
558 0 - 23 -
TABLE IV (continued)
Millimetres Inches
Symbol Description
Min. Max. Min. Max.
CC Video reference point
(odd fields)
4.078 0.15657 0.16055
525-60 3.977
625-50 3.987 4.082 0.15697 0.16071
DD Video reference point
(even fields)
4.115 0.15799 0.16201
525-60 4.013
625-50 4.017 4.113 0.15815 0.16193
EE Sync reference point
(odd fields)
2.550 0.09642 0.10039
525-60 2.449
625-50 2.459 2.554 0.09681 0.10055
FF Sync reference point
(even fields)
2.586 0.09783 0.10181
525-60 2.485
625-50 2.489 2.584 0.09799 0.10173
8. Electrical parameters
8.1 Modulation system

The video information shall be recorded in the form of an r.f. signal frequency modulated

by the processed video signal. The instantaneous frequencies of the r.f. signal shall vary

linearly with respect to the amplitude of the modulating signal.
8.2 Signal processing

8.2.1 A signal processing system consisting of elements specified by this clause shall contain, in

order of signal flow, the following elements.
8.2.1.1 A means to modify the burst amplitude.
8.2.1.2 A video pre-emphasis network.

8.2.1.3 A linear frequency-modulator having constant deviation with respect to modulating fre-

quencies.

8.2.1.4 An amplifier of the frequency-modulated carrier to provide alternating-current drive to

the video and sync record heads.
---------------------- Page: 13 ----------------------
558 - 25 -
c0 I E C 1982
8.2.2 Burst amplitude
A means shall be used to
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.