Problem with projector during conference

[dnslynn]

The video to the projector is composite baseband (not modulated). It comes from the satellite receiver though a video distribution amp.
The problem was not very apparent during the between conference broadcasts that had 4:3 aspect ratio. The moment the conference broadcast switched on (letterbox 16:9 aspect ratio) the problem became very apparent.
I will try to see what kinds of broadcasts make the problem worse. But there doesn't seem to be a schedule for conference re-broadcasts, so I'll just have to see if I can get lucky and find one. I will check during the next CES broadcast (which we don't normally project in the chapel).

Thanks

[russellhltn]

But there doesn't seem to be a schedule for conference re-broadcasts

Useing the Offical Communicaiton Libraray, you might check the schedule for other areas of the world. They have broadcasts this coming weekend. Maybe, just maybe, they'll do it on the US system as well. Otherwise, check the BYU-TV schedule since they carry BYU-TV when nothing else is on.

The problem was not very apparent during the between conference broadcasts that had 4:3 aspect ratio. The moment the conference broadcast switched on (letterbox 16:9 aspect ratio) the problem became very apparent.

Which is puzzling since composite video is just composite video. It doesn't have "modes". So unless the projector is reacting to the back bars top and bottom, I'm not sure why the difference.

You might also explore the various sub-menus and features on the projector to see if there's any video processing settings that could affect this. But I can't think what. The fact you can't see this on the other projector makes me think that it's not a problem in the rack but a ground loop between the projector and the rack.

It might not hurt to try different outlets, or get a tester to make sure someone didn't swap hot and neutral on that outlet.

For kicks and giggles, you could also try feeding the projector from a tuner rather than the composite feed. If the rack isn't too far away, run an extension cord so the projector is running off the same outlet. Maybe there's some excessive noise on electrical system and that's causing the issue. It may get worse when you change the load by turning off the lights for conference.

[StevePoulsen]

dnslynn, I tend to suspect the projector, primarily because of the change in the problem when you switched between them. Can you give me details on the model numbers of the projectors you were using and which one was behaving erratically?

As to diagnosis of the problem, The FM may in the end need to contact a contractor, though their first stop is to contact the broadcast support team at CHQ. (this is the same team that you can contact with issues during a broadcast) 801-240-3454.

[russellhltn]

I tend to suspect the projector, primarily because of the change in the problem when you switched between them.

Quite possibly a factor, but the other projector might have had better isolation from the power line ground and failed to complete a ground loop. I think I have the same model as the problem one, but I normally drive it from a DVD player. Never experienced any problem with it.