Toner Cable VM2551 Frequency Agile Modulator - Manual

VM2551
Agile Commercial Video Modulator
969 Horsham Road l Horsham, Pennsylvania 19044 USA l Phone: 215-675-2053 Fax: 215-675-7543 l [email protected]
The VM2551 is a vestigial sideband, agile modulator with synthesized visual and aural carriers and a full +55
dBmV output level.
Designed to accept composite NTSC video and audio inputs from a satellite receiver, video server, off-air
demodulator, DVD player, VCR, or similar source, the VM2551 features front panel video and audio over-modu-
lation indicators and level controls to permit easy setup of modulation levels.
The use of frequency synthesis provides complete frequency agility in the range of 54 to 550 MHz using off-air
or CATV (STD, IRC, or HRC) channel plans. In compliance with FCC regulations, channels that fall in specified
aeronautical bands feature automatic frequency offset.
The use of a superior SAW filter in the IF circuitry allows adjacent channel operation when used with other mod-
ulators or signal sources. A composite IF loop following the SAW filter and before signal conversion to the final
RF output channel allows the insertion of scrambling equipment or an IF switch to provide switchover for EAS
operation.
If required, the audio preemphasis may be defeated to allow use with a baseband stereo encoder or the normal
internally generated aural carrier can be disabled and an externally sourced 4.5 MHz signal can be applied to
the rear panel input.
These features, combined with a carefully designed low distortion output stage, provide reliable and economical
performance in an adjacent channel +55 dBmV cable television or private cable environment.
Features
• Frequency agility with 82 channel coverage from 54 MHz to 550 MHz.
• CATV (STD, HRC or IRC) or off-air channel plans selectable from front panel.
• Front panel control of channel selection, video level, audio level, output level, and
A/V ratio.
• High output power to +55 dBmV.
• Designed for multiple modulator installations.
• Emergency Alert System (EAS) ready with IF composite loop.
• Composite IF loop to accommodate a variety of encryption systems.
• Audio and Video LED overmodulation indicators.
• Automatic channel offsets where specified by FCC regulations.
• SAW filtering to ensure quality performance.
• External source 4.5 MHz aural input.
• Defeatable pre-emphasis for use with baseband stereo encoders.
• Front panel monitor connection at -30dB