Upwards of 200' video run, from camera to booth to projector.

[Lambda]

I've been asked to figure out how to run video from a camera on stage, to a video switch in the booth, then to a projector on main pipe. What concerned me was the long run, which we've had trouble with last year. Last year we tried to send video from the booth to main pipe with coax cable, but the video signal wasn't strong enough. We ended up using an old VCR in the booth to modulate it into RF channel 3, and another VCR clamped to the pipe tuned to ch. 3 and connected to the projector. Ugly, but the video got through.

The system with the VCRs is still in place, but I'd like to be a bit more professional this time (and we don't have two extra VCRs for the camera run). A search on CB leads me to believe that the best solution is either to use coax cable with BNC connectors (with RCA adapters), or to use video baluns with cat5 cable. I'm leaning toward the baluns and cat5 cable, because last year's run with coax didn't work. Could it be that we just used cheap cable?

I've been asked to figure out how much all of this will cost. In my searching, I gather that I can rent high-end BNC coax cable. Can I rent the baluns and cat5 too, if they are the best solution? I'd like to rent as much as we can to keep our costs down. Can anyone recommend anyplace in Rhode Island that we can rent from? (note that we already have the camera)

Just to recap, the signal originates at the camera, goes 100' (plus slack so the cameraman can walk around) to the video switch in the booth (a passive device), then proceeds another 100' to the projector on the main pipe.
Also, about the term "main pipe". It doesn't seem that anyone here uses that term, but at our venue it refers to the lighting truss that hangs FOH, just downstage of the end of the stage. What's the actual term for it? Would it just be the 4th electric?
I appreciate your help, I haven't actually worked with video (or renting) very much and this is a bit new to me.

 

[museav]

It sounds like you're dealing with composite video from both the camera to the switcher and from the switcher to the projector but it is probably best to be sure, so is the video involved composite video, S-Video, HDMI, SDI, FireWire, etc.?

Another factor may be how long the cabling would be in place and where it runs. Anything left in place longer than 30 days would likely not be considered temporary by local code while if the cable has to run through walls or in plenum spaces then it has to be properly rated,

You might be able to rent coax cables but if that is all you're renting you may pay an exorbitant amount as the potential of dealing with damaged or failed cables and connectors could be a huge risk relative to the actual device cost. So unless somebody has some cables laying around that they'd be glad to get anything for then you may be better off purchasing them.

 

[Lambda]

It sounds like you're dealing with composite video from both the camera to the switcher and from the switcher to the projector but it is probably best to be sure, so is the video involved composite video, S-Video, HDMI, SDI, FireWire, etc.?

Another factor may be how long the cabling would be in place and where it runs. Anything left in place longer than 30 days would likely not be considered temporary by local code while if the cable has to run through walls or in plenum spaces then it has to be properly rated,

You might be able to rent coax cables but if that is all you're renting you may pay an exorbitant amount as the potential of dealing with damaged or failed cables and connectors could be a huge risk relative to the actual device cost. So unless somebody has some cables laying around that they'd be glad to get anything for then you may be better off purchasing them.

Yes it is all composite video, the regular old yellow RCA connector, coming from a consumer handheld video camera. And just to be clear, it isn't a video switcher we've got in the booth, just a passive A/B switch. It won't be there long, just for a single event, one day only.
The last time we tried to do this, we used a long coax that someone had lying around his basement, one of the regular ones with the F-connector. Could it have been the connectors, and subsequent adapters to change them to RCA plugs, that caused the signal loss? If I splice some nice BNC connectors onto the existing cable, would it fix all that? Or is there no fix for cheap cable?
I've gotta know this for sure, there can't be any trial and error here. Whatever I tell them, they're expecting it to work the first time.

 

[dbrown]

switch to coat its not that expensive and if you have a local cable they might make you a deal. stay with rg6 not not rg59 the other advantage is its 75 ohms like compost and s-video so little lost. for my porjects i have run 100 to 200 lengths with no loss, but be carefull of ground loops with what ever you do.

Yes it is all composite video, the regular old yellow RCA connector, coming from a consumer handheld video camera. And just to be clear, it isn't a video switcher we've got in the booth, just a passive A/B switch. It won't be there long, just for a single event, one day only.
The last time we tried to do this, we used a long coax that someone had lying around his basement, one of the regular ones with the F-connector. Could it have been the connectors, and subsequent adapters to change them to RCA plugs, that caused the signal loss? If I splice some nice BNC connectors onto the existing cable, would it fix all that? Or is there no fix for cheap cable?
I've gotta know this for sure, there can't be any trial and error here. Whatever I tell them, they're expecting it to work the first time.

 

[gbdesign]

Also, about the term "main pipe". It doesn't seem that anyone here uses that term, but at our venue it refers to the lighting truss that hangs FOH, just downstage of the end of the stage. What's the actual term for it? Would it just be the 4th electric?

FOH Truss would be a good name for your "main pipe". Electrics are numbered from the Proscenium going upstage...1st Elect, 2nd Elect, 3rd and so on.

 

[Nelson]

I had a similar situation a while ago. I used RG6 coax with F-RCA adapters on each end and it worked well. After that event, I bought a pair of simple, inexpensive baluns so I can use the cat-6 that we already have in place instead of running coax. I haven't tried the baluns yet, though, so I can't say how well they will work.

 

[BillESC]

I just finished an installation where a camera in a chapel's balconey will be used to feed video to the Parish house. The cable run was 638'. I used a Kramer video amplifier and RG6Quad cable. No problems. A quality amplifier makes all the difference.

 

[Lambda]

I just finished an installation where a camera in a chapel's balconey will be used to feed video to the Parish house. The cable run was 638'. I used a Kramer video amplifier and RG6Quad cable. No problems. A quality amplifier makes all the difference.

The amplifier is a pretty good idea. I thought about building one last year, but didn't find the time. Stupidly, I never checked prices on them and I didn't realize how inexpensive they are. If I were to use one of these, would it be best placed at the camera to send a strong signal down the line, or at the projector to amplify a weak signal?

Edit: I forgot to mention the other video signal. Since I'll be using an A/B switch in the booth, I might also send video from our computer as the B source. That will be coming from a VGA to composite adapter, which is the same thing we used last year that couldn't make it the 100 feet. So maybe I would be better off with the amp at the projector that way I'd only need one.

 

[BillESC]

Put the amp after the switcher.

I just finished another installation where two laptops are switched as sources, the feed is then split to feed both a video projector and a 42" monitor. I put the amp between the switcher and splitter.

 

[Lambda]

Thanks for the help, I'm going to go with the coax with RCA adapters and the amplifier. I was thinking this amplifier.
It's designed for multiple displays, but it does amplify the signal. It's really inexpensive, which the council will like, but will it be guaranteed to work? It seems to me that it's TOO cheap, and it might not actually work. I have to figure this out now, if it doesn't work the first time I test it, it might as well not work at all.

 

[BillESC]

That's a toy (read: you get what you pay for)

A real tool for the application will run you around a hundred bucks and let you sleep nights.

XE-12L - All Distribution Amplifiers - Kramer Electronics

 

[Lambda]

That's a toy (read: you get what you pay for)

A real tool for the application will run you around a hundred bucks and let you sleep nights.

XE-12L - All Distribution Amplifiers - Kramer Electronics

That one there looks like exactly what we need. Where exactly can I order this? I don't see any link on the page. Do I have to call to find the price out? Only reason I'm asking is I have to have the complete project cost analysis and bill of materials by tuesday, and if they won't pick up their phones until then, then I'll be up the proverbial creek without the proverbial paddle.

 

[museav]

The signal losses are going to potentially happen in several ways. The cable itself will have a loss that varies with distance and the physical cable. The switcher likely has some loss. Connectors and adapters can cause losses, sometimes equivalent to many feet of cable and even more so with poor quality connectors and connections. I've been through this myself and the difference between two identical cables of the same length but with one using cheap connectors poorly installed and the other using high quality connectors installed using the proper tools and procedures can be significant.

In addition to the losses are the signal strength the sources output, which can vary, and also the signal strength the projector requires for a good image. For composite video a 1V peak-to-peak signal is standard, however there is nothing guaranteeing that the camera or the VGA to video scan converter actually output a 1Vp-p signal.

RG-6/8/11 versus RG-59 does typically make a difference in the cable loss incurred, however the question becomes is it a significant enough difference at the frequencies associated with composite video and at the cable lengths involved to be necessary or to justify the additional cost and physical size of the larger, lower loss cable? Probably not in this case, but if you had the choice of comparable RG-59 and RG-6 coax cables for about the same price then it would make sense to go with the RG-6.

If the issue were just the camera and not the computer then you would probably want to put the amp at the camera, however if the problem is associated with both the camera and the computer or with just the computer, then any line or buffer amp added should probably be after the switcher so it can help both sources.

Bluntly, composite video out of a camera via an RCA and from an inexpensive scan converter that is run any distance and then projected as a large image is not going to look that good. Back in the days of composite video and analog SD broadcasts, broadcast scan converters were thousands or tens of thousands of dollars, high quality equalization DAs were used, cables and connectors were carefully matched and installed, etc. and those images projected were still of limited quality, so you can guess what happens when you have lower cost components, added adapters, etc. It will work, but you do need to be realistic in your expectations of the resulting image quality. If the camera and computer have other outputs (component, HDMI, etc.) and you want better image quality then you might want to look at a different approach.

 

[Lambda]

In addition to the losses are the signal strength the sources output, which can vary, and also the signal strength the projector requires for a good image. For composite video a 1V peak-to-peak signal is standard, however there is nothing guaranteeing that the camera or the VGA to video scan converter actually output a 1Vp-p signal.

Bluntly, composite video out of a camera via an RCA and from an inexpensive scan converter that is run any distance and then projected as a large image is not going to look that good. ... It will work, but you do need to be realistic in your expectations of the resulting image quality. If the camera and computer have other outputs (component, HDMI, etc.) and you want better image quality then you might want to look at a different approach.

Just for fun I decided to look at the composite output of the camera on an oscilloscope. I'm not quite sure how a video signal measurement is obtained (a gray test card?), but the level of the camera's signal is 2.1v peak-to-peak when pointed into a white light, and about 0.75v with the lens cap on. The signal that appears to determine luminance/chroma looks to be about 4mhz, although I'm not sure of this because that's approaching the limits of my scope. That signal repeats at about 16.5khz.
The VGA converter, I don't have yet so I don't know about it. I also don't have an easy way to figure out exactly how much of the signal is lost in the cable. It's times like this when I wish I had a portable oscilloscope to bring to school.

Quality isn't really a concern. It's been done before in this auditorium, so we know what to expect. (It was before the days of anyone on tech now, so unfortunately I have no idea how it was done last time). The screen isn't really that big and the audience isn't expecting high-def quality either.
The camera is an old one, and it only has composite out. The scan converter I'm looking at only has composite and s-video. In addition, the video switch only supports composite. So without spending more money, there aren't a whole lot of options other than composite.

 

[rwhealey]

That one there looks like exactly what we need. Where exactly can I order this? I don't see any link on the page. Do I have to call to find the price out? Only reason I'm asking is I have to have the complete project cost analysis and bill of materials by tuesday, and if they won't pick up their phones until then, then I'll be up the proverbial creek without the proverbial paddle.

Full Compass and B&H both carry Kramer.

 

[Lambda]

I should correct a mistake that I made in my last post when I measured the level of the composite signal. That measurement of 2.1v was under no load, when the camera is connected to the television the signal actually measures exactly 1 volt.
The picture is actually clear on the television down to about 0.3 volts, and below that it gets dimmer, at 0.1v it's still visible but very dim. At 0.05v, the picture disappears completely.
However, for the tv to recognize the signal, it has to be 0.3 volts or higher.
That may be a bit confusing. If you start with a normal signal and lower the level, there will be a picture down to 0.05 volts. But if you start at 0 volts and raise the level, it must be 0.3v before an image is displayed. For all intents and purposes, the level of the signal at the end of the line should be higher than 0.3 volts. That is the way it is for my television, at least. If I get the chance to lug the oscilloscope to school then I'll try this experiment with a projector.

As for solving my problem, I've decided to use the affordable Kramer PT-102VN (it supposedly has up to 6db of gain, which I hope should be enough to compensate for the long cable), and RG-59 cable + the appropriate connectors. It's all affordable enough that I think the council will approve it. If they don't, I suppose I'll be looking for two more VCR's.

 

[jbrem003]

Simple answer, you need a video Balun. KeyDigital and Geffen are both companies that make them. They transmit your video over a Cat5 cable and reincode it at the other end. Much cheaper than trying to buy the cable itself in a 200' length.

One example:

Gefen, LLC - Composite Video Extender

 

[Lambda]

Well, the event was today. The system worked perfectly, the picture was of decent quality and much better than I expected. The video amplifier worked out quite well, and with some quality BNC connectors & cable, delivered an excellent signal to the projector. The image from the VGA converter was a bit blurry, but sharp enough that I could read all the numbers on the test pattern.

If it weren't for the quicktime video freezing up, our computer crashing, our backup computer refusing to output to the VGA converter, the light board's buttons failing, and the guy working the camera constantly pointing it at the wall or zooming in on the curtain, I'd have said the event went well. But my part worked, and for that I thank you.

 

[museav]

Simple answer, you need a video Balun. KeyDigital and Geffen are both companies that make them. They transmit your video over a Cat5 cable and reincode it at the other end. Much cheaper than trying to buy the cable itself in a 200' length.

One example:

Gefen, LLC - Composite Video Extender

I agree that video over UTP is a good alternative but you can get a good quality 200' coax (Belden 1694A or 1505A) with BNC connectors from several sources for well under the $199 price of that Gefen unit.

Also, the video over CAT devices like the one linked do not encode, decode or 'reincode' the signal, they are simply an interface to allow the signal to be carried on a different cable. In the case of that particular device it apparently also provides some variable signal amplification. It is important to understand that such devices do not convert the signal to Ethernet data as that is why they cannot run through standard switches, routers, hubs, etc.