Digital Processing Systems DPS-295: Difference between revisions

Latest revision as of 19:42, 19 February 2026

Description

The Digital Processing Systems DPS-295 is an infinite window multi-format transcoding TBC designed for cable, broadcast, and post-production facilities. It eliminates timebase error while providing a single platform capable of interfacing various composite and component video standards including NTSC, SVHS, Y/C-688, Y/C-629, and CAV (MII or Betacam).

The DPS-295 features advanced digital circuitry including chroma noise reduction, chroma edge enhancement, automatic adaptive 3D dropout compensation, and an adaptive comb filter. The adaptive comb filter maintains full 6.0 MHz luminance bandwidth for transcoding and processing in all modes.

A built-in 48-pattern component test signal generator provides a complete set of true multi-format component test signals including SMPTE bars, EIA bars, multiburst, pulse and bar, convergence grid, ramps, and various measurement patterns.

Digital effects include posterization, black stretch, sepia, and solarization, each with 16 levels of adjustment. Freeze modes include frame, field (with selection of 1-3 captured fields), and variable strobe.

An optional waveform monitor board enables digitally synthesized waveform, vector, and component parade displays, with the ability to download digitized video data to a PC for automated signal measurement or multimedia integration.

The unit is housed in a 1U rackmount enclosure and provides comprehensive remote control options via RS-422 ES-buss or RS-232 serial interfaces, plus a GPI input for remote freeze triggering.

Photos

Specifications

Video Processing

Parameter	SVHS/DUB Input	NTSC Input
Sampling	8-bit, 14.318 MHz, Component	8-bit, 14.318 MHz, Component
Frequency Response	±0.25 dB (FCC Multi-burst), 6 MHz (-3 dB)	±0.5 dB (FCC Multi-burst), 6 MHz (-3 dB)
Differential Phase	<1°	<2°
Differential Gain	<1%	<2%
K-Factor	<0.5%	<1%
S/N Luma (weighted)	>58 dB	>58 dB
Synchronizing Range	—	Infinite
Residual Timebase Error	—	<15 ns

Test Signal Generator

Parameter	Specification
Frequency Response	±0.1 dB (FCC Multi-burst)
Differential Phase	<0.25°
Differential Gain	<0.25%
Luma Non-linearity	<1% (5-Step)
Chroma Non-linearity	<0.25%, <1° (NTC-7)
Y/C Delay	<5 ns
K-Factor (2T)	<0.25%
S/N Luma (weighted)	>70 dB

Proc Amp Controls

Control	Range
Luminance Gain	+6 to -40 dB
Set-up (Black Level)	±20 IRE
Chroma Gain	+6 to -40 dB
Hue	±60°
Y/C Delay Horizontal	±1 µs
Y/C Delay Vertical	+1 to -2 lines
System Phase	±17 µs

Effects

Effect	Range
Posterization	16 levels
Black Stretch	16 levels
Solarization	16 levels
Sepia	16 levels
Strobe	0-100 frames

Physical

Parameter	Specification
Dimensions (W × H × D)	17" × 1.75" × 20" (43.2 × 4.4 × 50.8 cm)
Rack Height	1U
Operating Temperature	0-40°C
Spec Temperature	10-40°C
Storage Temperature	-40 to 75°C

Inputs

Connector	Signal	Level
NTSC-1 (BNC)	Composite NTSC	1V p-p, 75Ω terminated
NTSC-2/DUB-C (BNC)	Composite NTSC or DUB chroma	1V p-p, 75Ω terminated
SVHS (4-pin Mini-DIN)	Y/C-3.58	Y: 1V p-p, 75Ω; C: 286mV burst, 75Ω
DUB-Y (7-pin)	Luminance	1V p-p, 75Ω
Ref. Video (BNC)	Color black	1V, Hi-Z loop-through

Outputs

Connector	Signal	Level
NTSC-1 (BNC)	Composite NTSC	1V p-p, 75Ω
NTSC-2 (BNC)	Composite NTSC	1V p-p, 75Ω
SVHS (4-pin Mini-DIN)	Y/C-3.58	Y: 1V p-p, 75Ω; C: 286mV burst, 75Ω
DUB (7-pin)	Y/C-688	Y: 1V p-p, 75Ω; C: 688 kHz, 230mV burst, 75Ω
CAV Y (BNC)	Component Y	Betacam: 714mV; MII: 700mV
CAV R-Y (BNC)	Component R-Y	Betacam: 700mV (75% bars); MII: 486mV (75% bars)
CAV B-Y (BNC)	Component B-Y	Betacam: 700mV (75% bars); MII: 486mV (75% bars)
Subcarrier (BNC)	3.58 MHz feedback	2V p-p, 75Ω
Advanced Sync (BNC)	Composite sync, 32 lines early	4V p-p, 75Ω
RGB (optional)	RGB with sync	714mV RGB with 286mV sync

Test Signal Generator Patterns

The built-in test signal generator provides 48 patterns:

#	Pattern	#	Pattern
0	SMPTE Bars	24	Modulated Ramp
1	EIA Bars	25	Demodulator Alignment Multi Ramp
2	Full Field Bars	26	FCC Composite
3	Bars/Luma Bars	27	NTC-7 Combination
4	Bars/Red	28	Multi-Pulse
5	Bars/Reverse Bars	29	Sin(X)/X
6	Bars/Timing (20T modulated pulses)	30	Timing Bowtie (±50, ±100...±250 ns markers)
7	Luma Bars	31	Matrix-1: Pulse & Bar, Bars, Modulated Ramp
8	Multi-Burst 60 IRE (0.5/1/2/3/3.58/4.2 MHz)	32	Matrix-2: FCC Composite, Bars, NTC-7
9	FCC Multi-Burst 100 IRE	33-40	Bounce 10/90
10	Luma Line Sweep (0-5.5 MHz with markers)	41-48	Bounce 0/100
11	Chroma Sweep (0-1.0 MHz with markers)
12	Pulse & Bar with Window
13	Convergence Grid
14	Super Black (0 IRE)
15	Black (7.5 IRE)
16	Gray (50 IRE)
17	White (100 IRE)
18	Red Field
19	Luma 5-Step
20	Modulated 5-Step
21	Luma 10-Step
22	Modulated 10-Step
23	Luma Ramp (0-100 IRE)

Input Modes

The DPS-295 supports three input processing modes:

HET (Heterodyne) — Used for all TBC applications when the subcarrier feedback is not used. Also suitable for synchronizer applications.
DIRECT — Used only in TBC applications when the subcarrier feedback from the DPS-295 is connected to the playback VTR.
SYNC — Used for synchronizer applications when the signal being processed does not require timebase correction. Provides better stability and Y/C separation with noisy signals.

Remote Control

The DPS-295 supports three remote control methods:

GPI — Contact closure or TTL input for freeze toggle
RS-232 — 9600 bps, 8N1, for PC-based control
RS-422 ES-buss — 38.4 kbps with even parity, for broadcast automation systems

The remote port uses a 9-pin D-sub connector with jumper-selectable RS-232 or RS-422 electrical interface.

Options

Waveform Monitor Board — Provides digitally synthesized waveform, vector, and component parade displays. Supports video data download to PC via serial port for automated measurement.
RGB Output Board — Adds RGB output capability (714mV RGB with 286mV sync) in addition to Y/R-Y/B-Y component outputs. Supports RGB-S (4-wire) applications via advanced sync output.

@@ Line 6: / Line 6: @@
 |images=Digital Processing Systems DPS-295 front angle.webp,Digital Processing Systems DPS-295 top.webp,Digital Processing Systems DPS-295 rear.webp,Digital Processing Systems DPS-295 rear angle.webp,Digital Processing Systems DPS-295 internal.webp,Digital Processing Systems DPS-295 internal 2.webp,Digital Processing Systems DPS-295 label.webp
 |year_released=1988
-|signal_standard=NTSC
+|av_system=NTSC
-|video_inputs=2× Composite (BNC), S-Video (Mini-DIN-4), DUB Y/C-688 (7-pin), Reference video (BNC loop-through)
+|frequency=60Hz
-|video_outputs=2× Composite (BNC), S-Video (Mini-DIN-4), DUB Y/C-688 (7-pin), Component Y/R-Y/B-Y (3× BNC), Subcarrier 3.58 MHz (BNC), Advanced Sync (BNC), RGB (optional)
+|power_avg=100
-|audio_inputs=None
-|audio_outputs=None
 |features=Infinite window TBC, full bandwidth (6 MHz) frame synchronizer, multi-format transcoding, adaptive comb filter Y/C separator, automatic 3D dropout compensator (DOC), chrominance noise reduction, chrominance edge enhancement, 48-pattern component test signal generator, digital effects (posterize/black stretch/sepia/solarize), freeze frame/field/strobe, digital proc amp controls with non-volatile memory, Y/C horizontal and vertical delay adjustment, subcarrier feedback for direct mode TBC, RS-422 ES-buss remote control, RS-232 serial control, GPI freeze input, optional waveform monitor board, optional RGB output board
 |description=The Digital Processing Systems DPS-295 is an infinite window multi-format transcoding TBC designed for cable, broadcast, and post-production facilities. It eliminates timebase error while providing a single platform capable of interfacing various composite and component video standards including NTSC, SVHS, Y/C-688, Y/C-629, and CAV (MII or Betacam).
@@ Line 26: / Line 24: @@
 |width=17 in
 |depth=20 in
-|power_voltage=85-132V AC
-|power_wattage=100W
 }}
@@ Line 254: / Line 250: @@
 * [[Digital Processing Systems DPS-290]]
 * [[:Category:Time base correctors and frame synchronizers|Time base correctors and frame synchronizers]]
+{{AV TBC
+|type=Line TBC
+|buffer_size=Infinite window
+|notes=Full-range timebase correction with infinite correction window
+}}
+{{AV TBC
+|type=Frame synchronizer
+|buffer_size=1 frame
+|notes=Full bandwidth (6 MHz) frame synchronizer
+}}
+{{AV input
+|label=NTSC-1
+|signal=Composite (CVBS)
+|connector=BNC
+|count=1
+|audio=None
+|location=rear
+|notes=1V p-p, 75Ω terminated
+}}
+{{AV input
+|label=NTSC-2/DUB-C
+|signal=Composite (CVBS)
+|connector=BNC
+|count=1
+|audio=None
+|location=rear
+|notes=1V p-p, 75Ω terminated. Also serves as DUB chroma input when DUB mode is selected.
+}}
+{{AV input
+|label=SVHS
+|signal=S-Video (Y/C)
+|connector=Mini-DIN-4
+|count=1
+|audio=None
+|location=rear
+|notes=Y: 1V p-p, 75Ω; C: 286mV burst, 75Ω
+}}
+{{AV input
+|label=DUB
+|signal=Y/C DUB color-under
+|connector=Hirose 7-pin DUB
+|count=1
+|audio=None
+|location=rear
+|notes=DUB Y/C-688 luminance via 7-pin connector; DUB chroma via NTSC-2 BNC input
+}}
+{{AV input
+|label=Ref Video
+|signal=Composite (CVBS)
+|connector=BNC
+|count=1
+|audio=None
+|location=rear
+|notes=Color black reference input, Hi-Z loop-through
+}}
+{{AV output
+|label=NTSC-1
+|output_type=Video
+|signal=Composite (CVBS)
+|connector=BNC
+|count=1
+|location=rear
+|notes=1V p-p, 75Ω
+}}
+{{AV output
+|label=NTSC-2
+|output_type=Video
+|signal=Composite (CVBS)
+|connector=BNC
+|count=1
+|location=rear
+|notes=1V p-p, 75Ω
+}}
+{{AV output
+|label=SVHS
+|output_type=Video
+|signal=S-Video (Y/C)
+|connector=Mini-DIN-4
+|count=1
+|location=rear
+|notes=Y: 1V p-p, 75Ω; C: 286mV burst, 75Ω
+}}
+{{AV output
+|label=DUB
+|output_type=Video
+|signal=Y/C DUB color-under
+|connector=Hirose 7-pin DUB
+|count=1
+|location=rear
+|notes=Y: 1V p-p, 75Ω; C: 688 kHz, 230mV burst, 75Ω
+}}
+{{AV output
+|label=CAV
+|output_type=Video
+|signal=Component (YPbPr)
+|connector=BNC
+|count=1
+|location=rear
+|notes=3× BNC (Y/R-Y/B-Y). Betacam: Y 714mV, R-Y/B-Y 700mV; MII: Y 700mV, R-Y/B-Y 486mV
+}}
+{{AV output
+|label=RGB
+|output_type=Video
+|signal=RGBS
+|connector=BNC
+|count=1
+|location=rear
+|notes=Optional expansion board. 714mV RGB with 286mV sync on 4× BNC
+}}
+{{AV voltage range
+|voltage_min=85
+|voltage_max=132
+}}
 [[Category:Digital Processing Systems AV devices]]
 [[Category:Time base correctors and frame synchronizers]]