Description
The Digital Processing Systems DPS-290 is a broadcast-quality rackmount time base corrector and frame synchronizer designed for use with U-matic, U-matic SP, VHS, S-VHS, and Hi8 machines. Available in single-channel (DPS-290) and dual-channel (DPS-290D) configurations, it provides standard composite, Y/C (S-Video), and component analog video (Betacam/MII) inputs and outputs simultaneously, enabling true transcoding between formats.
A key feature is the adaptive comb filter Y/C separator circuit, which maintains true luminance bandwidth exceeding 5.5 MHz even with composite signals. This allows the DPS-290 to function as a frame synchronizer for camera and satellite feeds without loss of high-frequency picture detail.
The DPS-290 includes Digital Recursive Noise Reduction (DNR) with separate luminance and chrominance controls, and a 3D Dropout Compensator (DOC) that accepts RF or TTL signals from VTR heads. Special effects include freeze frame, freeze field (1-3), variable strobe, and film mode strobe which simulates 3:2 pulldown for a film-like appearance.
The DPS-291 is an identical variant that excludes the DNR/DOC features, with an optional DNR/DOC-290 module available for field upgrade.
Front panel controls include a backlit LCD display, rotary control wheel, and dedicated proc amp buttons. All settings are stored in non-volatile RAM and maintained through power cycles. A 10-event scene memory allows instant storage and recall of complete proc amp configurations.
An optional RGB board enables RGB input and output capability in addition to the standard Betacam and MII component formats.
Specifications
| Parameter | Specification |
|---|---|
| Video Input (NTSC mode) | 1V p-p, 75Ω |
| S-Video Input (Y) | 1V p-p |
| S-Video Input (C) | 286mV p-p burst level |
| Component Input (Betacam Y) | 714mV p-p, 75Ω |
| Component Input (Betacam R-Y/B-Y) | 700mV p-p, 75Ω |
| Component Input (MII Y) | 714mV p-p, 75Ω |
| Component Input (MII R-Y/B-Y) | 486mV p-p, 75Ω |
| Reference Video Input | 1V p-p (loop or 75Ω termination) |
| DOC Input | RF or TTL selectable |
| GPI Freeze Trigger | TTL or contact closure |
| Bandwidth | 0-5.5 MHz (+0.5/-3dB), all modes |
| Signal-to-Noise | >58 dB |
| Differential Phase (Composite) | <2° |
| Differential Gain (Composite) | <3% |
| Differential Phase (S-Video/CAV) | <1° |
| Differential Gain (S-Video/CAV) | <1% |
| K Factor | 1% (all input modes) |
| Residual Time Base Error | <15 ns |
| Serial Interface | RS-232 @ 9600 bps, 8N1 |
Proc Amp Controls
| Control | Range |
|---|---|
| Video Level | ±3 dB (±30%) |
| Black Level | ±20 IRE (±125mV) |
| Chroma Level | ±3 dB (±30%) |
| Hue (Chroma Phase) | ±30° |
| Horizontal Position | ±1 µs |
| Red Color Balance | ±10% |
| Blue Color Balance | ±10% |
| Y/C Horizontal Delay | -620 ns to +420 ns (70 ns steps) |
| Y/C Vertical Delay | -2 lines to +1 line |
Genlock Timing
| Parameter | Range |
|---|---|
| Horizontal (Main TBC) | ±4 µs |
| Subcarrier (Main TBC) | ±360° |
| Subcarrier (Second TBC) | ±60° |
Environmental
| Parameter | Specification |
|---|---|
| Operating Temperature | 0-40°C |
| Specification Temperature | 10-40°C |
| Storage Temperature | -40 to 75°C |
Connections
Rear Panel
The rear panel provides the following connections:
- NTSC Video Input - BNC connector for composite NTSC video from VCR or other source
- NTSC Video Output - BNC connector for time base corrected composite output
- S-Video Input - 4-pin Mini-DIN for S-VHS/Hi8 input
- S-Video Output - 4-pin Mini-DIN for time base corrected S-Video output
- Genlock Video - BNC loop-through for external reference (black burst or color bars)
- DOC Pulse Input - BNC for dropout compensator RF/TTL signal from VTR
- Multi-Function I/O - DB-15 HD connector with breakout cable for:
- Component Y Input/Output (Green BNC)
- Component R-Y Input/Output (Red BNC)
- Component B-Y Input/Output (Blue BNC)
- RGB Sync Input (Grey BNC, optional RGB board required)
- Advanced Sync Output (White BNC, 32 lines early)
- GPI Freeze Input (Black RCA)
- Remote - DB-9 for RS-232 serial control (Pin 2: TX, Pin 3: RX, Pin 5: GND)
The second TBC channel (DPS-290D) duplicates the video inputs and outputs but shares the genlock reference with the main channel.
Model Variants
| Model | Description |
|---|---|
| DPS-290 | Single-channel TBC with DNR/DOC |
| DPS-290D | Dual-channel TBC with DNR/DOC |
| DPS-291 | Single-channel TBC without DNR/DOC (field-upgradeable) |
| DPS-291D | Dual-channel TBC without DNR/DOC (field-upgradeable) |
Optional accessories:
- DNR/DOC-290 - Field-installable noise reduction and dropout compensator module for DPS-291
- RGB Board - Enables RGB component input and output
Menu Settings
The DPS-290 provides extensive configuration through its front panel menu system:
- Video Mode - Process (default) or Bypass
- Y/C Horizontal Control - -420 ns to +620 ns
- Hot Switch - Auto-freeze on input signal loss
- Color/Monochrome - Force black and white output
- Vertical Blanking - Narrow (9 lines) or Wide (21 lines)
- Video Out - Normal or Force Black
- Burst Status - Enabled or Disabled
- Noise Reduction - Luma/Chroma on/off combinations
- Unit Genlock Mode - Internal or Auto (external)
- Comb Filter - On (full bandwidth) or Off (bandpass)
- Select CAV Output - Betacam, MII, or RGB
- Select CAV Input - Betacam, MII, or RGB
- DOC Status - Enabled or Disabled
- DOC Delay - No delay or 1 line
- GPI Mode - Enabled or Disabled
- Echo Mode - RS-232 acknowledge commands
- Advanced Sync - 32 lines early or 0 lines
- Unit Address - 1-32 for serial control
- Y/C Vertical Delay - +1 to -2 lines
- VITS Comb Control - Bypass or Bandpass mode
