drjim
Premium,MVM
join:2000-06-13
Torrance, CA
clubs:
| [OTA] Commercial Multi-Channel Converters?
Hi, everybody
The place I work at has a TV distribution system feeding several hundred TVs. Rather than buying a set top box for each TV, the guy who maintains the system asked me if I knew of any "head end" type systems that could convert all the channels we get OTA, and feed it into the system.
I've searched a bit, but I've been out of the TV biz for so long my search skills in that area are pretty rusty!
Thanks!
--
One man's Magic is another man's Engineering. |
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Jahntassa
What, I can have feathers
Premium
join:2006-04-14
Conway, SC
| I haven't been in a head-end in a while, but i'd think you'd pretty much need a demodulator (tuner) and modulator for each channel.
What's your TV distribution system doing now? Was it just taking an antenna input and splitting it out to the several hundred TVs? |
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LBDSL
Lightning Bolt
VIP
join:2002-01-07
Auburn Hills, MI
| And even taking that though process a step further, depending on what the current system does, it may be possible to just get a basic converter box for each OTA channel, connect them to an RCA modulator to place each on on a analog channel, and router that into your current set up.
Probably not the sexiest way to do it, but may be the lowest cost option.
--
Lightning Bolt Technologies |
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drjim
Premium,MVM
join:2000-06-13
Torrance, CA
clubs:
| reply to drjim
The current TV systems just takes the input from the antenna and runs it through a distribution system consisting of splitters and line amps. I suggested just getting seven boxes for the seven channels they want, and feeding them with a splitter, amplified if required, and then combining them and feeding it back into the system we already have. I was told the problem was rack space, and they were looking for an "All-In-One" box that was 2 or 3 RU, and could be fit into the small amount of space in the existing rack. I told them I didn't think such a box existed, but that I'd ask around.
The consensus from here, and some people I know in the industry, is get the seven boxes, and *find* some rack space. *I* think we could do it, but the powers-that-be have it in their pointy little heads that *somebody* must make such a box that will magically solve our problems, and fit into the existing rack space.
I think they're nuts.....
--
One man's Magic is another man's Engineering. |
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Jahntassa
What, I can have feathers
Premium
join:2006-04-14
Conway, SC
| In any industry where they do this thing with any sort of seriousness, all-in-one solutions are often not what they want.
Why would a head-end of a major company (figure cable or otherwise) want to spend $30k on a single box that can do what you want for say, 10 channels, and then get screwed when the frame goes down? It simply isn't feasible.
Nevermind the fact that what you're looking to do is extremely specific. Most places that want to do their own internal rebroadcasts have several sources that they may want to come from, so it wouldn't work very well.
You might be able to find some modulator / demodulator units that have multiple modulators / demodulators in them, but they could still be fairly expensive.
The consensus you've found is right. They either need to suck up and find some space, or do it another way. |
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drjim
Premium,MVM
join:2000-06-13
Torrance, CA
clubs: | Oh, I agree with you 100%.
This is what happens when you have a preponderance of Mechanical Engineers running an Electronics-based program. They just don't "get it".
--
One man's Magic is another man's Engineering. |
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Joe12345678
join:2003-07-22
Des Plaines, IL | reply to drjim
new tv don't need a box can you look at them to see if they can do digital and just get boxes on the ones that can't |
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tschmidt
Premium,MVM
join:2000-11-12
Milford, NH
 ·Hollis Hosting
 ·Verizon Online DSL
·Fairpoint Communic..
| reply to drjim
If you are going to do conversion you are going to need to do it on a per channel basis. Doing it at the head-end means you need as many converters/modulators as there are channels. Many DTV stations broadcast sub channels. If you need to deliver those each sub channel will consume an RF channel.
Am I to assume these are old TVs that need digital converted to analog? If so I'd argue you are much better off doing the conversion at the TV. That way your system distributes programs in digital format. As TVs are replaced that will have access to HDTV.
If you are just redistributing over the air, rather then using QAM you can use OTA converter boxes to upgrade analog TVs. My guess you can get a good deal on a bulk buy from a distributor. They retail for only $40-60.
/tom |
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drjim
Premium,MVM
join:2000-06-13
Torrance, CA
clubs:
| It's also a question of cost. There's only 12 TVs in the "VIP Cabins" that really need to be done. As unpopular as it will be, they're going to have to tell the crew to buy their own converter boxes and 220-to-110 transformers. Replacing those 12 TV's will cost about $2000 each for the TV, shipboard mounts, and installation. Yes, I know a new TV can be purchased for much less, but they have to capable of running on 220VAC, have to have approved mounts, and the labor to install them is a fixed amount.
It's getting to be a no-win situation, and I'm glad I'm not the "System Owner".
--
One man's Magic is another man's Engineering. |
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BB User
@rr.com
| reply to drjim
You'd need a few 1 RU units and it won't be cheap.
This 1 RU unit will receive upto 4 8vsb digital off-air channels and output them on ASI:
»www.megahz.com/SpecSheet.asp?str···rSolID=4
This 1 RU unit will receive the ASI output from the previous receiver units and output up to 24 analog RF channels in the right config:
»www.megahz.com/SpecSheet.asp?str···olID=302 |
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BB User
@rr.com
| reply to drjim
You could also go with the modular Blonder Tongue systems.
Headend catalog:
»www.blondertongue.com/headend/Headend.pdf
BT AQD chassis is a 3 RU chassis that has 8 slots for 8vsb demods to take digital off-air and convert it to baseband.
AQD 8vsb demod PDF:
»www.blondertongue.com/htdocs/med···/AQD.pdf
BT HE chassis is a 2 RU chassis that has 12 slots for modulators that take the baseband and put it on a channel.
HE chassis catalog:
»www.blondertongue.com/headend/heSeries.pdf
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drjim
Premium,MVM
join:2000-06-13
Torrance, CA
clubs:
| Thanks! That's exactly what I was looking for.
When they see the price on this stuff I'm hoping (for my friend who's the "System Owner") the PHB's will rethink just getting seven boxes and a bunch of splitters/combiners!
--
One man's Magic is another man's Engineering. |
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BB User
@opera-mini.net
| Remember
The convertors will all out put either baseband signal on RCA jacks or channel 3/4 RF.
To get a sequential channel line up you'll need either prcessors to convert the channels 3/4 to the RF channels you need or modulators to covert the baseband to RF channels you need. |
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fozngoof
Premium
join:2003-07-08
Temple, TX
·AT&T Southwest
| reply to Joe12345678
said by Joe12345678  :new tv don't need a box can you look at them to see if they can do digital and just get boxes on the ones that can't Going off of what Joe said.
I am assuming none of the TV's are capable of receiving the digital signals? |
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drjim
Premium,MVM
join:2000-06-13
Torrance, CA
clubs:
| Yeah, they're all older analog only 32" CRT TVs. Just heard back from one of my buddies at a former employer that Holland Electronics makes equipment that's fairly inexpensive. I'll have to forward that to my friend who's in charge of the TV system.
--
One man's Magic is another man's Engineering. |
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tschmidt
Premium,MVM
join:2000-11-12
Milford, NH
·Hollis Hosting
·Verizon Online DSL
·Fairpoint Communic..
| said by drjim :they're all older analog only 32" CRT TVs. Too bad: weight, size or power consumption is not an issue to justify conversion to digital flat panel sets. 32" CRT TVs are larger then some apartments 
/tom |
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drjim
Premium,MVM
join:2000-06-13
Torrance, CA
clubs: | Not at a per unit replacement cost of $2000. |
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cypherstream
Looking forward to the future of things.
Premium,MVM
join:2004-12-02
Reading, PA
clubs: | Check some of the modular pieces on this page:
»www.cencom94.com/gpage6.html |
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Joe12345678
join:2003-07-22
Des Plaines, IL | reply to drjim
220 - 110 to dc for the box seems like over kill 220 to dc is better. |
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Joe12345678
join:2003-07-22
Des Plaines, IL
1 edit | reply to drjim
if that is case then you will not want to pass the full OTA as SD only with no sub channels on a $2000 HD tv will suck. |
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