Audio/Video specifications?

[rmrichesjr]

Yes. We only have one set of doors. But the way it works is when they are opened, the cultural hall sound is turned on and slaved to the chapel. If the doors are closed, then the cultural hall is controlled by it's own control panel. Before, you probably had to throw a switch to for that function.



Complain. They really should be set up right. But from what I've seen, I suspect the video guys just eyeball the adjustments. With any luck, they'll be back to do final setup. They rushed it to get it working for this weekend.

A few years ago, at my previous stake center, the contractor/installer set things up and did a rough tuning of the system. Three weeks later, Sound Design, the consultant, came to do fine tuning. With luck, somebody will have arranged for Sound Design to come prior to conference.

Are the colors too wild even when viewed from an RCA jack compositie baseband video outlet? If so, the problem is likely in the video distribution amplifiers or upstream. If the colors are okay on an RCA jack but too wild on an F-connector RF jack, the likely culprit would be the trimpots on the modulators. In that situation, an STS might consider asking the help desk for permission to adjust them in advance of the fine tuning by the consultant.

[russellhltn]

Three weeks later, Sound Design, the consultant, came to do fine tuning.

I know that's the case with sound. I'm not sure if they do that with the video.

[rmrichesjr]

I know that's the case with sound. I'm not sure if they do that with the video.

Good point. My mistake.

If the colors and other adjustments on the front of the modulators are indeed out-of-whack, someone with help desk and/or FM group permission could use an oscilloscope and maybe a few other pieces of test equipment to adjust them.

[russellhltn]

someone with help desk and/or FM group permission could use an oscilloscope and maybe a few other pieces of test equipment to adjust them.

Takes more then a o-scope. More like a service monitor or analyzer. Some serious, specialized gear. Only someone who makes a living doing cable systems would have one.

[skiptaylor]

I was told by the FM manager that I'm to make no adjustments or modifications to the existing system.

So that fixes that.

[rmrichesjr]

Takes more then a o-scope. More like a service monitor or analyzer. Some serious, specialized gear. Only someone who makes a living doing cable systems would have one.

Actually, you can get VERY close with just an oscilloscope. You feed a stationary image into the modulator. The receiver's menu would work pretty well. You look at the waveform of a baseband composite video signal straight from the receiver. Then, you compare that with the output of a demodulator (a VCR or tuner would work quite well). Make sure both outputs are properly terminated with a 75-ohm resistive load. Adjust the color level and video gain controls until the post-modulator-and-demodulator signal looks exactly like the pre-modulator signal. Then, look at the two signals with a monitor and fine-tune until the images look exactly the same.

Of course, that's all academic at this point, because the FM group has withheld permission to make any adjustments. Hopefully, it can get properly fixed soon.

[russellhltn]

Maybe a little better then the Mark 1 eyeball, but I'm not sure by how much. My main concern is that the VCR contains some rather sophisticated processing and may be hiding some issues from you during the adjustments. Most importantly you need a static test signal that contains a bright white.

And that's just for video adjustment. You've still got audio to do as well as adjusting the RF output so it doesn't clip but is close to the level of the neighboring channels.

[skiptaylor]

It's been an interesting day. We had training on our new audio/video system.

I learned a few things, but already knew a lot of it. The consultant and I had a pretty good discussion about a few things though. Really a nice and intelligent man. One of the first vendors that I've met and felt at ease with. Probably because he actually LISTENED!

On the satellite signal, we found the Eb/n0 to be 11.3db, signal level is at -61db. The picture is still weird looking though. Color is overdriven and slightly bloomed would be a good way to put it.

It appears the vendor didn't install a few things that were supposed to be in the a/v closet. There's a long list of things they have to come back and fix or install. One is the RF output panel I was looking for.

Looks like this may be workable over time. Some of the suggestions I've received on here will be a help as well.

He said many of my suggestions have been implemented in the new Stake centers as they are being built. *sniff* I want one.

Just thought I'd pass all this on. All of you have fun with the GC broadcasts this weekend!

[rmrichesjr]

That's great you had a good talk with the consultant. The consultants are usually great. The contractors that do the installaton are also pretty good, especially if you bribe them. Bringing them a box of donuts can help them be much more local-member-friendly.

An Eb/No of 11.3 is quite good. You should have essentially perfect reception at that level. Let's hope the fixes the consultant identified will solve the remaining problems.

[skiptaylor]

Does anyone know what department in the Church develops the specifications for the Meetinghouse audio/video systems?

(no longer any need to reply)