foyer monitor system transmission problems

[polson136]

The "foyer monitor system," as we call it, consists of several TVs in the foyer, nursery, and prayer room. These monitors can display either the video output from the lighting booth or the output of a camera located above the sound booth. We recently redid the system and have run into some difficulties. Sorry about the length of the message.

Old system:
Composite video outputs from the booth and the camera went to the back room in the office to an input selector. From there it went into a VCR, along with the audio output from the sound booth, and came out as analog RF. The coax line went out of the back room, but still within the office, it got split 5 ways. Four of them went straight down into the cafe, and went to monitors 1 and 2. One of them also went to an area near monitor 7 (this monitor was not used for this purpose at this point), and the other got split 3 ways and went to monitors 3, 4, and 5. The last cable up in the office went to monitor 6.

This system stopped working at one point, and we eventually figured out that the problem was the VCR. When we were figuring all of this out we knew very little about the system, since we don't even know who it was that set this thing up. We swapped out the VCR for an RF modulator that we had, and the system worked again. We didn't look carefully at picture quality, so I don't remember what it looked like, and at this point we didn't even know that there was audio in the system at all. The controls were in a very unwieldy location, so we moved them to make them more useable.

Revised system:
We moved the input selector and the RF modulator from the back room to the light booth, then used the line that was running from the booth to the back room as our primary output line from the input selector, and plugged it directly into the huge mess of y splitters in the ceiling of the office, thus bypassing the back room entirely. We reran the line from the camera to go to the booth and didn't worry about hooking up the audio at this point.

This is the first time that we noticed video quality problems. That does not mean that this is the first time that they were there. The video quality was bad pretty much across the board. Worse in some areas than others. We then reran all of the cable to make it more logical, and we made use of some 4 way amplifiers that we had lying around.

New system:
Everything up to the RF modulator stayed the same. The output from the booth ran from through the kitchen to the missions kiosk (the only place in the area with power). We installed the first 4 way amplifier here, with legs going to monitors 1, 2, 6, and the 3-way splitter in the nursery. The last leg, which went near monitor 7, but wasn't actually plugged in to anything, was left disconnected. This dramatically improved video quality across the board, but it was still snowy in the nursery and prayer room. We put the second amplifier between the nursery rooms. That dramatically increased picture quality there. That made picture quality acceptable everywhere. (The prayer room was "good enough". When we eventually hooked up monitor 7, which is an HDTV, it was terrible, and understandably so.)

Then we hooked up the audio. The sound in monitors 1, 2, 5, and 7 (when we eventually hooked it up), was fantastic. With monitors 3, 4, and 6, you can just barely make it out if you turn the volume way up and tune out the static. If you plug in a different TV to the same line, it is fine. (We don't want to swap TVs because 1-4 are hung) I took an iPod and plugged it in to each of the TVs, and it worked. I plugged it into the RF modulator, and it was only half static in the TVs that didn't work. I should mention that the iPod is stereo, while the booth output is only mono. In order to hook up monitor number 7, we had to use a y splitter. We used it on the lines running to monitors one and two, which were previously crystal-clear. After that, there was some snow present, although not enough to be unuseable.

Does anyone have any ideas on how to fix the sound? I apologize if I accidentally was a little vague anywhere and would be happy to clarify any of the above post.

[petereit]

Any chance that you could budget several hundred dollars and "do this right?"

[prochlea]

Any chance that you could budget several hundred dollars and "do this right?"

Any chance this will include switching over to SDI?

[petereit]

Originally Posted by prochlea

Any chance this will include switching over to SDI?

LOL!! Not necessarily.

But it would definitely include a central video distribution hub of some kind.

[polson136]

Originally Posted by petereit

Any chance that you could budget several hundred dollars and "do this right?"

Not a chance, although I would like to hear what your ideas are, so that I know for in the future, and we may end up using some of those ideas. If one of your ideas is to use something better than analog RF, I know.

Also, what do you mean by a "central distribution point"? All of the controls are in the same location - finally, they weren't before. We just don't have a line running from every single TV back to the control center. If we were to do so, it would involve lots more cable and enlarging several holes that go through brick walls.

The primary thing that I am concerned with right now is the audio issue on some TVs. There is an update on that. Someone (probably me) didn't plug in one of the amplifiers. The video is now crystal clear (even on the HDTV), and the audio is greatly improved in the areas that were bad, and is still good in the areas that were good.

[prochlea]

I would start by checking all of the connections and splitters in the bad areas. You could also try swapping amplifiers around to see if the problem follows that...

[polson136]

It could be related to that, but I am inclined not to believe so because if we plug a different TV into the same cable, it works. The reason why we don't just swap out TVs is that they are hung from the ceiling, and it would be nice if we didn't have to change that. Also, if we plug something in to the sound for the composite video input on those same TVs, it is perfect.

[prochlea]

well - if the same cable works fine on one TV and poorly on the other, I'd say you've got a problem with the TV. The RF tuner could be having problems in the bad TV - or the jack could be loose on the circuit board...

[petereit]

Glad to hear you got it working better. Yes, the ideal situation is to have a dedicated cable running from one centralized device designed for signal amplification and distribution -- especially in an RF setup where every device added in the chain can seriously degrade the signal.

And if you want my REAL recommendation, just search the forums for posts from "petereit" containing the word "SDI". Everyone here is getting as tired of hearing that sermon as I'm getting tired of preaching it.

[polson136]

SDI sounds like a great idea in a world with an unlimited budget.

As far as a centralized distribution point goes, we were trying to do that as much as we could. Basically, what we have is controls which are now in our video booth (they weren't originally, they were about as far out of the way as possible), with that output running through the RF modulator, then going to a 4-way amplifier. One leg is going to the nursery (this is either the longest or second longest leg in the system), where there is another amplifier which goes to the nursery monitors. The reason why it is all done that way is that it didn't make sense to us or the ones who originally did the system to run three cables all the way back. They had just a three way splitter. We added the amplifier.

We have trouble with one on the first amplifier and two (of three) on the second.

[petereit]

SDI is only expensive if you don't place any value on your time and if you don't count the cost of pain, frustration, down-time and lost productivity.

Considering all that, SDI is the CHEAPEST way to go.