D2 (4fsc) FORMAT (IEC 60B (Sec) 200)
D2 (4fsc) FORMAT
A composite digital recording system with conventional analogue inputs and outputs. Internal A/D and D/A conversion uses 8-bit quantising at four times the sub-carrier frequency. Four digital audio channels are provided with 20-bit quantising at 48 kHz. Metal particle tape is used in cassettes conforming to the D1 outline. This approach extends the recording time for a given tape length (and hence size of cassette) by a factor of almost three compared to the D1 system.
| Signal system |
| Digital, composite. |
| Scanner |
| Geometry |
Helical |
| No. of rotating heads |
4 or 8 * |
|
| Scanner diameter |
96.4 * |
mm |
| Rotation speed |
lOO * |
rev/s |
| Tracks/revolution |
4 * |
|
| Head-to-tape speed |
30.4 |
m/s |
| Video track angle |
6.13 |
degree |
| Track width |
35.0 |
µm |
| Track pitch |
35.0 |
µm |
| Azimuth |
±15 |
degree |
| Tape Properties |
| Coercivity |
1500 |
Oe |
| Type |
Metal particle |
| Width |
19.01 |
mm |
| Thickness (total) |
13 (max) |
µm |
| Tape Consumption |
| Linear |
131.7 |
mm/s |
| Areal |
0.15 |
m²/min |
| Shelf volume |
717 |
cm³/h |
| Electrical Characteristics |
| Shortest wavelength |
0.79 |
µm |
| Input data rate |
142 vid 3.85 aud |
Mbit/s |
| Packing density |
2532 |
bit/mm |
* Value for a typical implementation. The standard specifies the foot-print on tape,
not how it is to be achieved.
IEC 60B (Sec) 200
