Digital Head End

[Robert]

Ok, TV experts, I need some advice. This question isn't actually for my church work, although it could apply. I work at a Student Union at a University where we basically have our own head end cable outfit serving our building. We have a DirecTV system of 12 tuners, a couple of computers for sharing announcements and happenings, and a few other video sources. All these things are modulated through Blonder Tongue Modulators and combined and sent out through a professionally installed distribution system. Channels 2-6, and odd channels 7-31. We are using new LCD TVs in the building to show the content. I have a background somewhat in TV, and I am aware of the limits and picture quality of standard def NTSC picture. What came up recently from some of our staff was the fact that we were not having a true HD signal quality picture on our displays, and if it was possible to have a system that modulated on the "Digital Tuner" on the TVs. One thing was our computers that show events going on, this signal is VGA being Scan Converted, then modulated and sent out. Well, of course the quality goes down, but with large fonts and carefully constructed graphics, the message can still come across.
Anyway, is it possible to have a digital modulation system with about 18-20 channels, how much would something like that cost, and how much would we really gain in quality over our current analog system vs. the cost.
Like I said, I think our current system is great for what it does, and I am not really advocating for a digital system at this time. If anyone has any advice for me I'd appreciate it.

Rob

[prochlea]

There are a Few companies that make quam modulators... Blonder tounge, ZeeVee, and contemporary research come to mind. You're definitely looking at $1-2K per channel, plus upgrading all your directv receivers to hd, and any upgrades necessary to your distro setup...

[petereit]

I was thinking the same thing as Pat: a BlackMagic VideoHub routing to ZeeVee QAM headends.

[Brad Weber]

Originally Posted by petereit

I was thinking the same thing as Pat: a BlackMagic VideoHub routing to ZeeVee QAM headends.

I understand the purpose of a router in large headends but there does not seem to be any SDI or machine control involved here so what would be the purpose of the Videohub?

Rob, if you have an analog RF or CATV distribution system then you may have to verify if the combiners, splitters, cable, etc. in the existing distribution system will support a HD system. While a typical ATSC/QAM system would assume around a 900MHz bandwidth, you would not be using that many channels so may not need that full bandwidth. However, losses and signal levels at the demodulators that may have resulted in less than perfect but usable analog signals may not work for some digital signals.

The ZeeVee HDBridge products are limited to S/PDIF digital audio and analog component video inputs, so you'd have to see how those inputs match your sources and what conversions may be necessary.

[Robert]

Thanks to all that replied to my post. It gives me somewhere to start looking at possibilities. Again, at this time I realized what we have and its limits, but I'm just trying to find answers to our other staff members questions. Also, I haven't even gotten to asking the company that installed our current system anything, but I might call them if I get a chance. Thanks again.

[rcourtney]

When modulating DirecTV look at Video Propulsion's Floodgate line.
http://www.videopropulsion.com/conte...odgate-directv