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nVision SG4424 HD Sync Synchronization Generator


Founded in 1982, LaserPacific Media Corp. is a digital HD motion picture and television post production facility offering a full range of services. From the first, LaserPacific made a commitment to introducing all-digital technological solutions to the Hollywood community.

The development of our innovative High-Definition Laboratory-which opened in 1998 and focused on 24p HDTV acquisition, editing and delivery-enabled our clients to make a relatively painless transition from standard-definition to high-definition.

(click thumbnail)Terry Brown, vice president of engineering for LaserPacific, poses with the facility's master control reference system that includes two nVision NV4000 frames holding five SG4424 HD slave sync generator cards.A critical component for the successful high-definition operations of our plant was a slave sync/pulse generator that could output all the necessary reference signals needed to synchronize the various ATSC formats in use. We also needed a sync generator that had some very specific relationships between 30 fps and 24 fps frame rates.

Since there were no 24p systems available off-the-shelf, LaserPacific partnered with a number of manufacturers, including nVision, to develop the critical components. At the same time, nVision was looking at the task of enabling its digital video routers to have vertical-interval switching of signals running at different temporal rates.


We started working with nVision to design a "next generation" sync generator. It was our task to define the various reference signals anticipated being used within our facility, and we worked closely with nVision's engineering staff, including Bob Hudelson, Chuck Meyer and Birney Dayton, to determine what the relationship of the sync components should be.

The result was the SG4424 HD Slave Sync Generator, which we installed as a prototype in late-1998, plus subsequent production-version updates and enhancements since that time. The SG4424 is designed to lock to an external NTSC or PAL reference signal from the master sync generator.

Internal jumpers let us select either Hi-Z or 75-Ohm impedance for the loop-thru PAL/NTSC references, as well as the type of HD sync format we need, including 1080i/60, 1080i/50, 1080p/30, 1080p/25, 1080p/24 and 720p/60, in the appropriate 0.1 percent offsets. Front-panel LEDs light when a valid signal is connected to the NTSC or PAL reference inputs, and when the module's outputs are locked to the selected reference input.

We now have a total of two NV4000 Series frames in our master control reference systems area, with a total of five SG4424 cards. This configuration provides us with eight NTSC/PAL sync reference sources, some of which are duplicated to provide redundancy. We distribute these sync sources via a dedicated router to approximately 100 destinations within our Hollywood plant.


To date, the system has proved to be completely reliable, a performance record that is essential for a 24/7 operation like ours. The SG4424 is total workhorse, and has been very solid since we first started to use it back in 1999-but, there again, all our nVision components have been extremely reliable.

Thanks to companies like nVision, we were able to fast track solutions for our 24p infrastructure, giving us a one-year head start in the industry. The nVision SG4424 HD Slave Sync Generator has become a totally integrated part of how we do business here at LaserPacific.

For more information, contact nVision at 530-265-1000 or visit