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Videotek DM-200A High-Performance Frequency Agile NTSC Demodulator
Representing over a quarter century of continuous commitment to meeting the requirements of the most demanding video RF engineers, Videotek offers the DM-200A high-performance demodulator. With a signal-to-noise figure better than 58 dB, the DM-200 series is ready to take charge at your laboratory bench, cable head end rack or broadcast facility. For use when you are performing FCC compliance testing, monitoring or recording offair signals, or rebroadcasting to your cable plant.
Features
- Full FCC 4.1 MHz bandwidth video for compliance testing
- Better than 58 dB Video SNR
- Differential gain: ≤1.0%
- Differential phase: ≤1.0°
- Multi-band tuning: VHF/UHF/Cable with HRC/IRC offset capability
- Proprietary high-performance SAW filter ensures optimal performance
- Simultaneous BTSC stereo and SAP outputs with LED presence indicators
- 4.5 MHz and composite audio outputs
- IF (45.75 MHz) loop enables use of external decoders
- Zero Carrier Pulse control allows depth of modulation measurements
- Synchronous detection
- Remote control via user-selectable RS-232/422/485 port
- Standards available: NTSC and PAL-M
Specifications
| Tuner |
| Tuning Range |
55.25 MHz to 860.00 MHz |
| Connector |
"F", 75Ω female |
| Input Range |
-10 to +25 dBmV |
| Maximum RF Input Level |
+30 dBmV |
| Fine Tuning Range |
±2 MHz in 64 steps |
| Frequency Stability |
±60 kHz typical |
| Channel Coverage |
VHF Channels 2-13 |
| UHF Channels 14-69 |
| Cable Channels 1-134 |
| Band Coverage |
Low, Mid, High, Super |
| Detector |
Synchronous |
| IF Loop |
+38 dBmV ±2 dBmV |
| Video |
| Video Output |
Two NTSC video outputs with negative sync and DC restoration |
| Connectors |
BNC 75Ω, source terminated |
| Level |
1V p-p, typical into 75Ω load |
| Adjustment Range |
±3 dB, minimum (front-panel control) |
| Differential Gain |
≤1.0% |
| Differential Phase |
≤1.0° |
| Frequency Response |
Up to 3.58 MHz ±0.6 dB (trap in) |
| Up to 4.1 MHz ±0.6 dB (trap out) |
| Chroma/Luma Delay |
±30 ns (referenced -170 ns) (w/perfect modulator) (trap in) |
| Signal To Noise Ratio |
≥58 dB @ +14 dBmV input level |
| Zero Carrier Output |
User selection ON/OFF; Location of Zero Carrier Pulse front panel selectable from line 10 through line 25 |
| Connector |
BNC 75Ω, female |
| Audio |
| Audio Line Outputs |
Balanced stereo left and right and SAP (source terminated) |
| Connectors |
Push-on pin connectors |
| Level |
0 dBm ±1 dB typical across 600Ω |
| Adjustment Range |
-16 dBm to +4 dBm |
| Frequency Response |
50 Hz to 12 kHz (stereo mode) ±0.5 dB |
| Stereo Separation |
>30 dB from 50 Hz to 10 kHz |
| Total Harmonic Distortion (THD) |
0.5% maximum, 1 kHz to 12 kHz |
| Signal To Noise Ratio |
≥60 dB |
| Monitor |
Audio jack; front panel level control |
| Audio Jack Impedance |
>16Ω level -25dBm Nominal, Adj. |
| Range ±15 dB |
| 4.5 MHZ Output |
+42 dBmV limited ±2 dB |
| Composite Audio Output |
0.5V p-p terminated 75Ω;
bandwidth 110 kHz ±1dB |
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