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From: ranma@noc.arc.nasa.gov (Robert Michael Gutierrez)
Newsgroups: comp.graphics
Subject: Re: Help with Video signal conversion a
Message-ID: <1991Jan6.033558.29246@nas.nasa.gov>
Date: 6 Jan 91 03:35:58 GMT
References: <28822@mimsy.umd.edu> <1091900008@cdp>
Sender: news@nas.nasa.gov
Reply-To: ranma@noc.arc.nasa.gov (Robert Michael Gutierrez)
Organization: The Saotome Ryu School of Martial Arts
Lines: 55

c.graphics is the wrong place for this...BUT...

ddulmage@cdp.UUCP writes:

> Please, do yourself (and your facilty) a big favor... Run fiber 
> optic instead of coax. There's no reason not to run fiber these 
> days, and it will give you tons of room to grow and save you a lot
> of grief as well. 

And will cost you tons of money also.

Seriously, why can't he use coax, especially since it will be limited to
one building.  There is absolutely no need to expend multi-year loans
on fiber, and there is NO video fiber distribution standard at this point
[point: I said VIDEO, not data!].  If he were to distribute to different 
buildings, even then I would think twice about fiber, unless you get into
a co-op agreement to share it with others (ie: data).

> I do contract eng. for a comp. that builds video
> walls, and I finally talked them into running fiber on some of their
> installations. 

And what if they want to expand.  They have only once source (essentally).
And the technicial labor expense of having fiber maintained...ugh!  Definitely
not for the staff boiler room 'engineer'.

Splice fiber breaks: Time Domain Reflectometer, $2,000+
		     Fiber fuser/splicer, another $2-4,000
		     Fiber splicing training, $1,000+expenses

Splice coax breaks:  Carpenters knife, $2.49 at Home Builders Supply.
		     BNC connectors and butt connector, $10.00/all.
		     Cordless Soldering Gun, $49.95 at Fry's Electronics.
		     Coax Splicing training, Good Chinese restraunt for lunch.

No comparison.  [Yes, I took lots of liberties here, but the point is the same]

> If you like to tinker, Signetics has just about all the IC's for
> the stuff you want (including very complete app. notes) in the
> linear and video books. I've used a chip that does exactly what
> you want, rgb>composite and it was painfully simple. The chip was
> made to do the conversion for consumer video cameras.

ie: No ready plug-'n-play stuff available.  Or at least, cheaply.

Seriously, even here at NASA Ames Research, our main video net is on 440mhz
RF modulated cable, and we have tons of room to expand on it, and it's even
a split run (two-way)!

Fiber is perfect for these ever-expanding data networks (FDDI) that would
otherwise be a nightmare on coax based runs, but it's just overkill for a
simple video distribution system.


   robert gutierrez