Sony DNW-A75 Maintenance Manual page 209

Data Arrangement on Program Tracks
Fig. A-2-2 shows the arrangement of data recorded on
helical tracks (program tracks). The size of each sector in
the figure is not the actual dimension ratio. For more
information on the dimension, refer to Fig. A-2-1.
The Betacam SX format uses an azimuth recording system
to perform high-density recording. In other words, two
heads with an azimuth angle of approximately 15 degrees
in the direction opposite to each other is paired to record
two program tracks (tracks A and B) during a turn of the
drum. Two-frame (1 GOP) video data and audio data are
recorded on ten (525/60) or twelve (625/50) program
tracks.
1 GOP (10 tracks)
VIDEO 2
2 tracks
SYSTEM DATA
AUDIO 4
AUDIO 3
Head Channel
DNW-A75/A75P
2 tracks
AUDIO 2
AUDIO 1
AUDIO 4
AUDIO 3
AUDIO 2
AUDIO 1
SYSTEM DATA
VIDEO 1
A B A B A B A B
525/60 System
Fig.A-2-2. Data Arrangement on Program Tracks
Each program track has eight audio sectors in the center.
A pair of video sector and system data is before the audio
sectors and the other pair is behind the audio sectors as
shown in Fig. A-2-2. Each channel of the audio sectors is
arranged in the longitudinal direction of the tape. Howev-
er, each channel is difficult to be influenced by the longitu-
dinal scratch on tape because it is divided into two sectors.
Two-frame video data is dispersed into twenty (525/60) or
twenty four (625/50) video sectors for recording, and four-
channel audio data is dispersed into twenty (525/60) or
twenty four (625/50) audio sectors for recording for every
channel. Edit gaps are set between the sectors so that each
channel can be edited independently. The control data for
executing the Multiple Tracing and the AUX data released
for the user are recorded in a system data area.
1 GOP (12 tracks)
VIDEO 2
2 tracks
SYSTEM DATA
AUDIO 4
AUDIO 3
AUDIO 2
A B
Head Channel A
A-2. Recording Format
2 tracks
AUDIO 1
AUDIO 4
AUDIO 3
AUDIO 2
AUDIO 1
SYSTEM DATA
VIDEO 1
B A B A B A B A
625/50 System
B A B
A-3