Digital Processing Systems DPS-290: Difference between revisions

Revision as of 05:19, 27 January 2026

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
Dimensions (W × H × D)	17" × 1.75" × 20" (43.2 × 4.4 × 50.8 cm)
Rack Height	1U
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

@@ Line 21: / Line 21: @@
 An optional RGB board enables RGB input and output capability in addition to the standard Betacam and MII component formats.
-|height=1.75 in
-|width=17 in
-|depth=20 in
 |weight=13.25 lb
 |power_voltage=85-132V AC
@@ Line 33: / Line 30: @@
 {| class="wikitable"
 ! Parameter !! Specification
+|-
+| Dimensions (W × H × D) || 17" × 1.75" × 20" (43.2 × 4.4 × 50.8 cm)
+|-
+| Rack Height || 1U
 |-
 | Video Input (NTSC mode) || 1V p-p, 75Ω