Wiring a new control room - SDI or Analog SDTV?

Cha-Ching!!
Baylink
Posts: 438
Joined: Wed Dec 15, 2010 3:21 pm

Wiring a new control room - SDI or Analog SDTV?

Post by Baylink » Sun Jan 02, 2011 1:54 pm

I'm hoping to get the chance this summer to replace the really mediocre control room in which I work (now does everyone understand why I'm not admitting to where that is? :-) with a slightly less mediocre control room.

All our gear is currently analog NTSC 4:3. Some of it has SDI cards available, some of it probably doesn't.

Is there enough extra value in SDI to merit switching to it in a one-room SDTV install? If so, is there enough of it still in the used market that I can get it relatively cheap?

And, generically, what's your go-to reference on engineering analog plant these days? Zettl?

User avatar
PID_Stop
Posts: 485
Joined: Thu Apr 01, 2010 11:58 am
Location: Syracuse, New York
Contact:

Re: Wiring a new control room - SDI or Analog SDTV?

Post by PID_Stop » Mon Jan 03, 2011 11:22 am

1) SD-SDI is component video; you don't have NTSC issues like luminance detail beating against the color subcarrier to worry about, and the picture is noticeably better.

2) SD-SDI is inherently stable with respect to levels and phases: you will spend very little time tweaking, and the output of your system can be an exact match to what goes in; older analog gear is going to be a constant battle of keeping everything in alignment as components age.

3) Using SD-SDI with embedded audio reduces the wiring and eliminates many of the typical causes of lip-sync error.

4) Chances are good that any SD-SDI gear you find will be newer (and closer to being supported) than their analog equivalents.

5) With stations and cable operations converting their plants from SD to HD, there are often deals to be had on the decommissioned SD gear. As it happens, last year I bought a batch of used DPS-475's on eBay for an insanely low price... they had been removed from a consumer satellite uplink, and needed only a couple of new fans to bring them right up to as-new condition.

Except for sentimental reasons (I have a stash of '50s and '60s Ampex and Scully machines in my attic, so this is a weak spot for me!), I can't come up with a good reason to go to the trouble of building up a facility as NTSC.

-- Jeff

Baylink
Posts: 438
Joined: Wed Dec 15, 2010 3:21 pm

Re: Wiring a new control room - SDI or Analog SDTV?

Post by Baylink » Mon Jan 03, 2011 1:10 pm

PID_Stop wrote:1) SD-SDI is component video; you don't have NTSC issues like luminance detail beating against the color subcarrier to worry about, and the picture is noticeably better.

2) SD-SDI is inherently stable with respect to levels and phases: you will spend very little time tweaking, and the output of your system can be an exact match to what goes in; older analog gear is going to be a constant battle of keeping everything in alignment as components age.
How do you zero-time SDI?
3) Using SD-SDI with embedded audio reduces the wiring and eliminates many of the typical causes of lip-sync error.
We are mostly a split-audio plant; lots of cameras, only 2 playback devices, so that's of slightly less import to me, but still useful.
4) Chances are good that any SD-SDI gear you find will be newer (and closer to being supported) than their analog equivalents.
Except, alas, for (as noted above) *all the gear I presently own*, nearly all of which is coming forward. And, as is customarily the case, there's no way I can get the budget to replace 6 CCUs, That Expensive Card In The Mac, and add That Other Expensive Card to the VT5. Much less swapping all 8 input cards in the Globcaster.
5) With stations and cable operations converting their plants from SD to HD, there are often deals to be had on the decommissioned SD gear. As it happens, last year I bought a batch of used DPS-475's on eBay for an insanely low price... they had been removed from a consumer satellite uplink, and needed only a couple of new fans to bring them right up to as-new condition.
Now that might make the thing worth looking into. :-)
Except for sentimental reasons (I have a stash of '50s and '60s Ampex and Scully machines in my attic, so this is a weak spot for me!), I can't come up with a good reason to go to the trouble of building up a facility as NTSC.
The question is, can I make a business (not engineering) case for spending the money. Better is, as you know, the enemy of good enough.

KE0MI
Posts: 31
Joined: Wed Aug 04, 2010 8:38 am

Re: Wiring a new control room - SDI or Analog SDTV?

Post by KE0MI » Tue Jan 04, 2011 11:26 am

The question is... How long can you keep the legacy equipment running?

I've yet to see a solid set of numbers that prove taking the programming to SDI from analog makes the station money(in ratings) unless a substantial quality problem exists with the analog. The same, unfortunately, can be said of going HD from SD SDI.

If the legacy switcher dies and a replacement delay card can not be purchased, how much down time and lost revenue is acceptable to management?

Baylink
Posts: 438
Joined: Wed Dec 15, 2010 3:21 pm

Re: Wiring a new control room - SDI or Analog SDTV?

Post by Baylink » Tue Jan 04, 2011 9:18 pm

In my case, the legacy switcher will be a Globecaster 8000, with a working hot-spare on the other side of the control room; the unit's still in production.

But the rest of your posting accords pretty much with how I was thinking about the thing...

Now, that said, I *do* have a really nice set of HK-355 studio camera heads I'll be happy to sell you cheap.

User avatar
PID_Stop
Posts: 485
Joined: Thu Apr 01, 2010 11:58 am
Location: Syracuse, New York
Contact:

Re: Wiring a new control room - SDI or Analog SDTV?

Post by PID_Stop » Wed Jan 05, 2011 1:05 pm

Baylink wrote:How do you zero-time SDI?
Pretty much the same way you zero-time NTSC. Naturally, you need a waveform monitor with an SDI input. But timing SDI isn't nearly as critical as NTSC, because most clean switches have at least a half-line timing buffer. You can have an SDI source 20 microseconds off, and never know the difference... compare that with NTSC, where two nanoseconds is a 16° chroma phase shift.
The question is, can I make a business (not engineering) case for spending the money. Better is, as you know, the enemy of good enough.
Okay, I didn't pick up on how much existing equipment you are planning to use. From the thread title, I thought we were talking about starting essentially from scratch.

We have the tee shirt for this sort of thing: started off NTSC, then wound up largely SD-SDI / embedded audio when we started centralcasting back in the Ackerley days (hello, Kelly!). Right now we're just finishing our HD production control. It's beyond insane to consider that when we built our present building in 1984, we filled the control room with about 25 racks of equipment, free-standing quad and 1" VTRs, an ACR-25, and two film chains. Now the HD equivalent (I use that advisedly, as the new plant can do so much more) fits in just six racks. Embedding the audio, so we aren't having separate distribution and switcher crosspoints, is one of the big factors. Only rarely do we need to split audio away from video, and we built in a way to do that as necessary. I definitely don't miss wiring Christmas trees or trying to solder audio wire to the back of a crowded DA frame... nor do I miss the telltale 6dB level drop from a bad connection, or out-of-phase audio.

From our experience, probably the best business case is that it takes less equipment to make SDI work, and because it is so much more stable and transparent than analog, radically less engineering time is needed to keep it operating within standards. If you do commercial production, that translates into happy clients who don't sit around waiting for somebody with a greenie to make the sources match up without jumping or changing colors.

-- Jeff

User avatar
PID_Stop
Posts: 485
Joined: Thu Apr 01, 2010 11:58 am
Location: Syracuse, New York
Contact:

Re: Wiring a new control room - SDI or Analog SDTV?

Post by PID_Stop » Wed Jan 05, 2011 1:12 pm

Baylink wrote:Now, that said, I *do* have a really nice set of HK-355 studio camera heads I'll be happy to sell you cheap.
It doesn't seem that long ago that we replaced our General Electric PE-350s with Ikegami HK-323s... later replaced with LDK-20s, and now with JVC GY-HD250s. These new critters just look like a pimple, compared to what used to sit on the pedestals! :D

-- Jeff

KE0MI
Posts: 31
Joined: Wed Aug 04, 2010 8:38 am

Re: Wiring a new control room - SDI or Analog SDTV?

Post by KE0MI » Wed Jan 05, 2011 2:15 pm

Now, If you really want to show a return, and you are not automated with the Globecaster already, and you see the potential of adding additional channels to the broadcast steam....(And can live without the tape operator, audio guy, etc...) and have some capital to invest, take the plant to HD SDI with embedded and make the station value increase! That is the most painful route to take, but it is the way the industry is heading.

User avatar
NECRAT
Site Admin
Posts: 2942
Joined: Sat Nov 17, 2007 9:13 pm
Location: Taunton, MA
Contact:

Re: Wiring a new control room - SDI or Analog SDTV?

Post by NECRAT » Wed Jan 05, 2011 2:18 pm

Another note that the SDI-Analog and Analog-SDI converters are SO much cheaper now adays than they used to be too.
You're better off building in SDI and converting for any "legacy" equipment you may have. The small Cobalts and AJA converters work really well, look clean for on air use, and are
very afforadble.

There is another side to this too, which hasn't been brought up that I saw when I skimmed over it. When you wire a plant for SDI video, you have to use cable for SDI video, namely Belden 1694A. (For very short video runs, Belden 1505A works). So you build your plant, using 1694A cable, and it comes time for the next big project, going HD. Guess what?
All that 1694A cable you ran, is also HD-SDI compatiable. So you build for future use as well.
http://www.necrat.us

"Arguing with an engineer is like mud wrestling with a pig. After a couple of hours, you realize the pig likes it"

Baylink
Posts: 438
Joined: Wed Dec 15, 2010 3:21 pm

Re: Wiring a new control room - SDI or Analog SDTV?

Post by Baylink » Wed Jan 05, 2011 8:53 pm

The odds we'll go HD, ever, are even lower than the odds I'll justify SDI, I suspect. That said, I *never* cheap out on speccing the physical plant; while I'm new to broadcast engineering type work, this is not my first rodeo otherwise. :-)

User avatar
PID_Stop
Posts: 485
Joined: Thu Apr 01, 2010 11:58 am
Location: Syracuse, New York
Contact:

Re: Wiring a new control room - SDI or Analog SDTV?

Post by PID_Stop » Thu Jan 06, 2011 1:10 pm

NECRAT wrote:When you wire a plant for SDI video, you have to use cable for SDI video, namely Belden 1694A. (For very short video runs, Belden 1505A works). So you build your plant, using 1694A cable, and it comes time for the next big project, going HD. Guess what?
All that 1694A cable you ran, is also HD-SDI compatiable. So you build for future use as well.
I agree with Mike, except that I would recommend Belden 1855 instead of 1505A for short runs. We found out the hard way that 1505A is very bad for analog video -- the chroma rolloff is surprisingly severe -- but both 1694A and 1855 will work reasonably well for NTSC. Compared to 1505A, 1855 is a bit less expensive and smaller in diameter, so it's very handy for wiring high density equipment (for example, if you have a bundle of 128 cables coming from patchbays to a routing switcher). The difference in maximum distance is minimal, especially since you would generally use 1694A for longer runs anyway. Better still, the Paladin crimper to install Kings BNCs on 1694A happens to also work for 1855.

-- Jeff

Baylink
Posts: 438
Joined: Wed Dec 15, 2010 3:21 pm

Re: Wiring a new control room - SDI or Analog SDTV?

Post by Baylink » Sun Jan 09, 2011 4:21 pm

Well, with the exception of VDA-out runs to floor monitors, I'm pretty sure that every bit of video I'll have to run will live within 4-6 adjacent racks. I'll have 2 HDMI long-runs from multiviewers to a pair of 50" LCDs, and some USB extenders for keyboards and mice, but that ought to be it.

My MPEG encoders and L-band modulator will be in those racks as well, and then I'll couple to whatever already runs from the mod to the SSPA/TWTA, which hopefully is Heliax, or maybe LMR. But all the video will be in those 4 racks; another reason why I couldn't see converting to SDI.

Baylink
Posts: 438
Joined: Wed Dec 15, 2010 3:21 pm

Re: Wiring a new control room - SDI or Analog SDTV?

Post by Baylink » Mon Jan 10, 2011 1:06 pm

And, subsidiary to this, I know that *someone(s)* has a library of 3-d models of video production equipment, for doing 3d mockups and walk-throughs, but my google-fu fails me; anyone know of a source for such models? .3ds or .skp preferred, but the software I'm looking at takes .obj as well, which I've never heard of.

TheSigma
Posts: 55
Joined: Thu Nov 19, 2009 10:59 am

Re: Wiring a new control room - SDI or Analog SDTV?

Post by TheSigma » Mon Jan 10, 2011 2:16 pm

Sketchup has a online "Warehouse" of models, have you looked there? Sketchup is also very easy to use if you want to make your own models.

http://sketchup.google.com/3dwarehouse/

Just searching the term "broadcast" brings up some random equipment, along with numerous seemingly unrelated items.....Happy searching.

Baylink
Posts: 438
Joined: Wed Dec 15, 2010 3:21 pm

Re: Wiring a new control room - SDI or Analog SDTV?

Post by Baylink » Mon Jan 10, 2011 3:28 pm

I found that earlier today, but had not tried the kw 'broadcast' yet, no.

I thought I remembered that one of the big resellers had assembled a collection of such models, but can't find that either.

Thanks for the pointer, though.

Post Reply