Video signal strength seems weak!!

[BLDunlap]

I have a Mac Pro (Mid 2012)
Processor 2x3.06 GHz 6-Core Intel
Memory. 64 GB. DDr3
Graphics. ATI Radeon HD 5770 1024 MB

We use this system at the church and run an overhead projector and three TV monitors from it. The overhead picture is perfect and operates flawless. However the three TV's are another story. Two of the TV's are in the foyer about 15 feet from the computer and the other is on the back wall of the sanctuary about 15 ft from the computer. Some days the two in the foyer are clear as a bell and on other days they are so jumpy and blurry we have to turn them off. The one on the back wall will seldom work. When it does it is in black and white and never color. It usually says on a few minutes and then begins floating a warning that there is no signal.

How can I boost the signal to these three TV monitors? They are all three being connected with coax TV cable. I now of churches that run multiple TV monitors throughout the building and don't seem to have a problem. What am I doing wrong? Or what do I need to do to make the connections more usable?

Thanks for your help!!

 

[bookemdano]

So I would have to imagine there is one video cable from the 5770 running into some kind of multiplexer box. Maybe that box needs to be replaced or can somehow have its output signal boosted. But unless I'm misunderstanding, the signal from your Mac Pro is probably fine. It's the multiplexer that is what is actually providing the signal to all of your monitors.

 

[BLDunlap]

So I would have to imagine there is one video cable from the 5770 running into some kind of multiplexer box. Maybe that box needs to be replaced or can somehow have its output signal boosted. But unless I'm misunderstanding, the signal from your Mac Pro is probably fine. It's the multiplexer that is what is actually providing the signal to all of your monitors.

Yes, the signal is coming from the video card and into a multiplexer box. Then the outputs from there are a VGA which goes to the overhead projector and an RCA plug that goes to an adapter/spliter that changes it to coax cable and that feed the three TV's. I already replaced the multiplexer box three times with no change in results. If I take my laptop and go up on a lift and attach it directly to the tv on the back wall the reception is clear and color but when I go back to the coax cable it is only in black and white and only stay for a short time.

 

[bookemdano]

You might have better luck posting this in a general AV forum, because the problem here is not related to your Mac Pro. It seems the multiplexer is not putting out enough output signal (especially once it gets split two ways and then split again 3 ways) to support the length of your coax cable runs.

That said, you can try something like this:

https://www.amazon.com/AuviPal-Distributor-Amplifier-Monitoring-Resolution/dp/B01MSQYHVI

(assuming the monitors all take a BNC input).