Order From - Multicom, Inc.

Order From - Multicom, Inc.
VM2552A BTSC STEREO VIDEO MODULATOR
The R.L. Drake Company now offers you superior stereo audio performance and extensive
channel capacity with the VM2552A BTSC stereo modulator. Another quality product from
Drake, long recognized for manufacturing products of enduring quality and reliability, the
VM2552A is designed and engineered to surpass the most demanding engineering
requirements and to provide your system with stereo audio capability.
- BTSC stereo audio with licensed dbx ® noise reduction.
Frequency agility with 82 channel coverage from 54 MHz to 550 MHz.
- High output power to +60 dBmV.
- Low noise floor for large, multiple modulator installations.
- Emergency Alert System (EAS) ready with alternate composite IF inputs.
- Auto switching from standard programming to emergency information with the Drake
IFM-80 EAS Modulator.
- Composite, video, and aural IF loops to accommodate a variety of encryption
systems.
- Manual audio and video level control or operator selectable AGC to maintain
modulation levels.
- Full front panel metering and level controls to simplify installation and operation.
- Automatic channel offsets where specified by FCC regulations.
- Video low-pass and SAW filtering to ensure quality performance.
- Video delay predistortion.
-
The Drake VM2552A BTSC Stereo Modulator is a high-quality, vestigial sideband unit with
synthesized visual and aural carriers. The frequency-agile VM2552A features 82 channel
frequency coverage up to 550 MHz allowing for front panel selection of standard CATV
channels 2 to 78 and 95 to 99. Monaural or BTSC stereo-operating modes may be utilized.
The BTSC stereo encoding incorporates professional dbx-tv® noise reduction circuitry
necessary for reproducing the BTSC signal with good stereo separation and audio fidelity.
The VM2552A is designed to accept video and stereo audio baseband signals from a satellite
receiver or other similar audio/video equipment. Both audio and video AGC can be selected
to maintain nearly constant modulation levels. Audio inputs can be either unbalanced or
balanced. A video low-pass filter and high-quality SAW filter eliminate adjacent channel
interference. These features, combined with a carefully designed output stage, provide
reliable operation in a densely crowded or cable environment.
VM2552A BTSC Stereo Video Modulator Technical Spec
Order From:
R
ifications
800-423-2594
www.multicominc.com
multicom@multicominc.com
IF
Frequency Range: 82 channels, 54-550 MHz channels 2-78 and 95-99
Output Level: +60 dBmV, (adjustable +50 to +60 dBmV)
Note: If an output level of less than +50 dBmV is
required, add an attenuator of the appropriate value to
the modulator output.
(Example: add a 10 dB pad for +45 dBmV output)
Output Impedance: 75 Ohms
A/V Ratio: Audio carrier -20 to -12 dB referenced to video carrier,
adjustable.
Frequency Stability: +/-10 ppm
Intercarrier Frequency: 4.5 MHz +/-10 ppm
FCC Frequency Offsets: Automatic, (+ or - or none, selectable via rear panel)
Spurious Outputs: -60 dBc typical -58 dBc minimum, measured at -15 dB
A/V ratio and with modulator output level of +60 dBmV
Broadband Noise: -75 dBc typical, referenced to video carrier (4 MHz BW
@+/-12 MHz offset
Video
Input Level for 87.5%: 1 Vp-p +/-3dB manual gain adjust with front panel
metering of AGC
Video AGC: Sync pulse gated. Automatically maintains 25%
modulation of sync pulse, which equals 87.5%
modulation for a full white level signal.
Input Impedance: 75 Ohm, return loss of 30 dB minimum
Frequency Response: 20 Hz to 4.2 MHz, +/-1.0 dB
Weighted Video S/N: 60 dB minimum
Differential Gain: +/-3% (10 to 90% APL)
Differential Phase: +/-3 deg. (10 to 90% APL)
C-L Delay: Meets groups delay predistortion requirement for
NTSC color transmission per FCC part 73.
Also complies with FCC rules: 76.605
Audio
Input Level for 25KHz Peak -10 to +10 dBm manual gain adjustment with front
Deviation: panel metering or AGC
Audio AGC: Adaptive attack, slow release provides 25 kHz peak
deviation for input levels of -10 to +10 dBm
Input Impedance: 600 Ohms balanced 300 unbalanced
Pre-emphasis and Noise 75µsec, professional dbx-TV®; companding of stereo
Reduction: subcarrier
Frequency Response: 50Hz to 14kHz, +/-1 dB
Order From:
R
800-423-2594
www.multicominc.com
multicom@multicominc.com
(Left or right channels)
Stereo Channel Separation: Typically more than 30 dB, 50 Hz to 14 kHx. 25 dB
minimum over operating temperature range.
Total Harmonic Distortion: 0.5% maximum
Hum and noise: -60 dBm minimum, referenced to 100% modulation level
Visual IF Loop
Visual Carrier Frequency: 45.75 MHz
Frequency Stability: +/-10 ppm
Output Level (45.75 MHz): +43 dBmV +/-2 dB
Spurious Outputs: -60 dBc minimum
Input Level (45.75 MHz): +43 dBmV
Input/Output Impedances: 75 Ohms, return loss greater than 20dB
Isolation: Greater than 60 dB
Aural IF Loop
Aural Carrier Frequency: 41.25 MHz nominal,
(-4.5 MHz +/- 10 ppm of visual carrier frequency)
Output Level (41.25 MHz): -28 dBmV +/-3 dB
Spurious Outputs: -50 dBc minimum
Input Level (41.25 MHz) +28 dBmV nominal
Iput/Output Impedances: 7 Ohms, return loss greater than 15 dB
Isolation: Aural carrier is greater than 60 dB below the visual
carrier with loop open and terminated
Composite IF Loop
Output Level (V carrier): +28 eBmV +/-2 dB
Spurious Outputs: -60 dBc minimum
Imput Level (V carrier): +28 dBmV nominal +30 dBmV maximum
Input/Output Impedances: 75 Ohms - Return loss greater than 20 dB
Isolation: Greater than 60 dB
EAS Input
Input Level: +28 dBmV nominal
Input Impedance: 75 ohms - return loss greater than 20 dB with this
port enabled
Auto Switching Level: Greater than 20 dBmV nominal
Isolation Between Composite Greater than 60 dB
and EAS Inputs:
General
Order From:
R
800-423-2594
www.multicominc.com
multicom@multicominc.com
AC Power Input: 115 VAC, +/-10%, 60 Hz, 35 watts
Operating Temperature Range: 0° to 50° C, ambient
Size: (W x H x D)
Standard: 1.75" x 19" x 14.3"
Weight: Standard: 8.8 lbs.
Metric: 4 Kg
dBx® is a registerd trademark, and is licensed by THAT Corporation.
Specifications, price, and availability are subject to change without notice or obligation.
DRAKE is a registered trademark of the R.L. Drake Company
Order From:
R
800-423-2594
www.multicominc.com
multicom@multicominc.com
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