OT- Video Transmitter

Jameson_Prod wrote on 7/10/2004, 1:22 PM
2 questions if I may......

1. Is there an affordable wireless way to transmit the video signal from a computer to an LCD projector?

2. If no such thing in question 1, how far can you run a composite video cable and/or a normal computer video cable (from computer to monitor or LCD) without major degradation.?

Thanks in advance.

Comments

Chienworks wrote on 7/10/2004, 1:29 PM
1 - Probably. Look in bargain/discount electronic stores. These sorts of things show up now and then, usually under $150 for the set.

2 - It depends on the cable and your definition of major degradation. Some folks say composite won't go further than 25 feet, others run hundreds of feet and claim the output is usable. If you could use S-Video instead of composite then you can probably go at least a few hundred feet without noticeable signal loss. Use the best cable you can afford.
John_Cline wrote on 7/10/2004, 1:43 PM
I'm assuming that you're talking about taking the VGA output from a computer and transmitting it wirelessly to an LCD projector. The answer is, no, probably not. Standard video is easy enough, but the bandwidth required to transmit a computer's VGA signal is going to be a real challenge. If your video card has either composite or S-Video outputs and you run at 640x480 or 800x600, then a standard 2.4Ghz video transmitter will work, but if you want to display the Windows desktop or text in a program of some sort, then it probably won't be readable.

If you have a high resolution LCD projector with a VGA input, you can run it for a couple of hundred feet with perfectly acceptable results IF you use a very high quality cable. If the projector will accept RGB/HV on BNC inputs, then you could get a VGA to BNC adaptor and run five absolutely EQUAL lengths of high-quality video cable (like Belden 8281) to the projector. I've done this and it works well.

Just curious, what exactly are you trying to do?

John
Orcatek wrote on 7/10/2004, 1:45 PM
Also a distribution amp may help on range along with well shielded cables.

kosins wrote on 7/10/2004, 2:34 PM
"how far can you run a composite video cable and/or a normal computer video cable (from computer to monitor or LCD)

Jameson.
Composite Video Cable:
Several hundred hundred feet (assuming it's a fairly good quality cable), with no problem.

RGB Cable:
20 feet, maybe as much as 50 or so.
Beyond that, I'd recommend you use an RGB signal amplifier. They are pretty cheap. Around 50~100 bucks, and they will let you run up to two or three hundred feet without any issues.
You'll spend more for the long RGB cables than the amplfier.
If you go that route, remember to grab a handful of D-sub "gender changers" too.
You'll be glad ya did.

I get a lot of stuff from this company:
They are "right around the corner" from me.

http://www.cablestogo.com/

:-)
johnmeyer wrote on 7/10/2004, 2:43 PM
If you just want to run comosite video a long way, the usual way is to use RG-6 (RF) cable and put an RCA to RF connector on each end. This gives you lower loss per foot and better shielding.

An even better solution is to use an unbalanced to balanced converter on each end. The device I use is made by Unicom and is called a "Video/Audio Adapter" part number VAA-U501-VA (here's a link: VAA-U501). It has thre BNC jacks on one end, and a single RJ-45 (i.e., a LAN connector) on the other end. You plug your two audio channels and your composite video channel into one end, and then plug a standard LAN Cat-5 cable into the other. The signal can travel over the for many hundreds of feet. The advantage of this approach is that Cat-5 cable is very cheap, and easy to snake around corner, through walls, etc. It also lets you get all three channels into a single cable.

I use BNC to RCA converters, since my connectors are all unbalanced RCA connectors.

This company also makes a model that accepts S-video input instead of composite, and that is what I would reocmmend you get (here's the link: S-Video Version
Jameson_Prod wrote on 7/10/2004, 3:20 PM
First...thanks to all for your suggestions.

For John (and others interested)

I am a sound man first. But I do alot of video on the side....(actually getting to where I do as much video as audio). This is the third or fourth time I have been asked to provide video for a large group as well as sound. With sound, I set up FOH in the rear of the room or auditorium and man everything from there. Typical concert style. But when I do video, I set up my normal FOH for audio and I have been setting up a laptop somewhere towards the front and center of the room where the LCD projector needs to be......running the audio from the laptop through direct boxes to the snake and back to the console. Obviously, I can't be in two places at once. Yes, I can get help to man the computer but I would like to be able to set my computer up in the back with me and run everything from there. (pay once instead of pay everytime) My problem is the video. How best to send the video only signal to the front and the LCD Projector.

My thoughts....wireless transmitter or build me some kind of video snake.

Thanks again for all the suggestions.
Jameson_Prod wrote on 7/10/2004, 6:55 PM
I found a 100ft svga cable for $69. (www.cablesnmor/svga-cables.html) Would this actually work? Seems a long way to run a monitor cable!!

Thanks again.
Chienworks wrote on 7/10/2004, 7:04 PM
In my church we run an SVGA cable about 150' to the projector. The picture is crystal clear. We did pay about $1.70/foot for the cable though.
epirb wrote on 7/10/2004, 7:07 PM
I've run 75' feet of svga cable in yachts from lower helm stations to upper stations. these are basicly 19" crt displays and plasma displays and had no problems.
Quality cables w/ good sheilding, very "noisey" environments.
dont know how it would be on an Lcd Projector with I take it a large projection area.
keep in mind,Vga cables dont like abuse ie: people stepping on them. we also use vga splitter boxes at the source which supposedly support runs up to about 200 feet.
MichaelS wrote on 7/10/2004, 10:34 PM
I'm often asked to provide "overflow" projection for funerals and such. Sometimes these calls come in just hours before the service, so there's not much preparation time.

It's probably the lowest quality of any option, but in a rush, I simply use a Radio Shack modulator to bump the the video and audio up to channel 3 and send it to the next building or room on common coax. If it's a long run, I'll put an RF amp at the front end of the coax. The end signal is not the greatest, but certainly usable in this type of situation.

I put the video up with either a projector or large TV. Elementary stuff, but it does work.
John_Cline wrote on 7/10/2004, 11:35 PM
Jameson,

Are you running graphics (i.e pictures or video) to the LCD projector or are you running the LCD projector as a large computer display to show programs running as in software demonstrations?

John
farss wrote on 7/11/2004, 3:12 AM
I've got a very small 2.4GHz LIPD transmiiter that mount on a camera's hot shoe, used mainly for rave parties. Receiver has a 9dB 'Golden Rod' yagi. Works quite well except as people move into the signal path the AGC cannot cope and you loose sync for a few frames but they just get a clear line to the reciever before they switch the feed on the mixer. Not broadcast quality but good enough for the job and beats having cameras destroyed when the party goers trip over the lead.
Jameson_Prod wrote on 7/11/2004, 6:19 AM
John......this event will be two short videos and at least one PowerPoint slide show. The videos I have created and would like to show from the desktop with WinDVD. Other things I have done have been software demonstrations and "how to".

Thanks again for all the ideas and help.