Finally Able to Post on our Recent Webcast Experience

[russellhltn]

From what I remember experiencing, a wrong termination tended to cause the picture to be too bright or too dim.

The way it should work is just like SCSI - one termination at the end. Everything else is in a "line" with no "Y".

The final termination could come from the devices used or with the cable itself.

[rmrichesjr]

My personal oscilloscope is really old and not calibrated, but I do have access at work. I will run some experiments and see what I learn.

I didn't think of terminating the unused outputs. I assumed they were totally isolated, but perhaps they are not.

Thanks for the suggestions.

But on the other hand, things seem to work quite well with my piggyback RCA patch cord. I realize it messes up the termination, but the encoded video and the video distributed throughout the stake center look pretty good. The patch cord places about a 3' stub with a second 75 ohm termination on the end of the line. If that is causing problems, what exactly should I look for in the image? I assume it would cause some kind of ghosting or something. If anyone has specific thoughts on what to look for, I would appreciate it.

(Sorry for not responding earlier. A wind storm and a tree falling across the street caused a 48-hour blackout at my house.)

In an ideal world, outputs of a DA would be totally isolated from each other. In practice, the designs I have seen use an output stage with a very low impedance (emitter follower or op-amp with feedback) output stage and a 75-ohm series resistor to each output connector. My hunch, and it's only a hunch, is a cost-reducer (who maybe didn't know better) decided to replace multiple 75-ohm resistors with a single lower value resistor shared by all output connectors. Terminating all unused outputs would work around that problem, if that is the problem.

I wouldn't think a 3' stub by itself wouldn't likely cause visible ghosting on an SD signal. If I'm doing the math right, 3' is just shy of a meter, signals in cable go about 0.6-0.7 times free-space speed of light, so even a round-trip reflection would take only about 10nanoseconds, a rather small fraction of the scan time of a single pixel. However, if the Y connector and stub were at the end of a long cable run with improper source termination, that combination of issues might cause ghosting.

If the cable run from the source to the Y connector is short, the Y connector would mostly cause a signal attenuation. That would cause the picture to be dimmer, closer to black. However, if there was an earlier problem that was causing too-high voltages, this might compensate to some extent. I would think the ideal solution would be correct voltage levels and termination all the way through. For the uncalibrated oscilloscope, you could calibrate it yourself using a DC voltage source and a DMM, provided the scope does DC.

[mellerbeck-p40]

2. We’re interested in the idea of a PTZ camera, so that video can be controlled from the technology closet, not just audio. Remember that the video needs to be clean as well. No decisions yet, but we’re looking.

I have been investigating this as well, the EVID70 looks very decent although I have been trying to find a cheaper controller than this one

http://picturephone.com/products/remote ... br300.html

(It seems a little overkill)

Anyone out there use the EVID70? Anyone find a cheaper PTZ controller?

Thanks, Michael

[ccmichaelson-p40]

I have been investigating this as well, the EVID70 looks very decent although I have been trying to find a cheaper controller than this one

http://picturephone.com/products/remote ... br300.html

(It seems a little overkill)

Anyone out there use the EVID70? Anyone find a cheaper PTZ controller?

Michael,

We purchased two EVI-D70's and the Sony BR300 device about 6 months ago. We ran wires back into the Stake Clerk's office and had a mini production booth. We also acquired a DataVideo SE-500 device and we were able to toggle between the camera, have 1 camera live while positioning the other camera with the BR300. I received rave reviews from those who watched Stake Conference.

If you do acquire the BR-300 device and the Sony EVI-D70 cameras, please contact me as I spent 15 hours attempting to get all the pins correct. One phone call into level III tech support gave me access to the exact pin placement (assuming you use CAT-5 using the RS-422 connection - which I highly recommend if you have to go some distance). Once I had the pin diagrams, I had both of them working within 10 minutes.

Good luck!
Cameron

[azpcox-p40]

Great thread and great info. We used a lot of the ideas in our last Stake Conference with the Webcasters and had a great conference.

Here are a few things we did differently that for us worked out very well.

1) Instead of the MXL2003s on boom stands for the choir, I fashioned a mic "pole" out of two 4ft 5/16 dowels connected together. (that's another post if anyone is interested). On the top of this, I mounted a Peavey Choir Mic (A friend let me borrow two PCM-2, black), I painted my dowels flat black and secured them to the front podium edges (old Stake Center), ran the wires back to the podium to which I had already run 4 mic cords. These two choir mics picked up the choir very well and were far enough back to not pick up individual voices. And they were practically invisible

2) Organ Audio - use the audio output on the organ if you have them. Look underneath the organ keyboard and you'll likely find the audio outputs. 1/4 inch for Aux output left, transformed to mic level, then run back to behind the choir loft (where all of our audio/video equipment is). This eliminated any guesswork as for organ audio.

3) Instrument mic - I had to run another mic cord for a violin that was part of the final musical number. That was also tricky to mix and then send to the other buildings as well as mic in the chapel at the same time. I ended up using a monitor feed from my mixer board and sent that into the sacrament table mic input so attendees in the cultural hall/Primary room/ RS room could all hear the violin.

4) We had two cameras as well, one for close-ups, one for wide-angle. One camera man on center camera to pan out as necessary. Came in handy as Elder Kikuchi had both old and new stake presidents come up with him.

5) We did have multiple tests for audio levels as well with the Stake Choir tests on the Sunday's before the actual conference. HUGE bonus as we kept testing new features.

6) The week before Stake Conference we had a test run. There was a seminary fireside and I asked the Stake President if we could use that as a "dry run", testing everything at the Stake Center and the other two buildings. This exposed a few flaws in our otherwise perfect plan, so we fixed those as best we could.

7) Backup audio stunk. Everything we did gave us grief. In the end, we decided that the 80% intelligibility was fine for backup. It may have been due to the voice lines as some have mentioned, and we tested and even got better voice quality when someone used their iPhone instead of the local phone line to join a conference bridge I had set up.

8) We used scan converters as well. Since I had a spare, I got creative at the Stake Center and ended up the night before using it as a titling generator along with the Video Mixer (MX-1). I had the agenda of who was talking when so I just faded up the name and their position as they started their talk, just like conference. The Coup de tat that really surprised everyone on the team was when the New Stake Presidency got up to talk. Because there was time while the old Stake Presidency was bearing their testimonies, I was able to generate the correct titles for them. People asked me if I knew who they were before hand it was that slick. I told them no, I just typed fast. This same system gave us lyrics to the songs, but Elder Kikuchi kept cutting the hymns down to a singe verse which made me delete pages I had prepared in Powerpoint.

All in all, a very successful experience. As we had a cable modem in the Stake Center, we were able to do a much higher bit rate since we have a 4 Meg upload speed. The 1.5 Meg downloads at the other sites gave us plenty of headroom. I had disabled all other connections except mine on the Family History firewall.

Things we might do in the next conference?

1) use a compressor of some sort for the Pulpit audio. This would allow the speaker to be quiet and load at the same time and compress the dynamic range before it goes into the audio system. For those of you who have heard Elder Kikuchi talk, he has a great dynamic range and the folks at the far sites kept asking me to turn it down slightly. Then he would get quiet and they'd ask me to turn it up. They can be expensive, so it's optional...

2) Match the cameras. I used a Canon XL-1 and a Sony 3CCD camera and although I tried to get the white balance manually adjusted on themm, I could still tell which camera was live just by looking at the color balance. These cameras were "free" (borrowed) and gave us plenty of experience in what we would like to do in the future.

3) Don't scare your team by changing stuff at the last minute with lyrics and titles. I did test it the Saturday night before at home, but I should have left that as a future task.

4) Backup Audio. Focus on the talking for backup audio. We'll figure it out and hopefully it's a simple fix.

I'm grateful for the enthusiasm on our team and am glad for the experience it brought me as well as the blessings this brought to the Stake. The Webcasters enabled mere mortals to configure and use it, and even though i am a networking expert during the weekdays, it was very pleasant to find that is really was so simple and elegant in setting up a webcast. Kudos to the Church for setting this up! Way to go!

Phillip

[russellhltn]

use a compressor of some sort for the Pulpit audio.

Watch e-Bay for a "gated compressor". The "gate" controls when the compressor changes it's gain setting. That way you don't hear the background noise creep up between speakers and get blasted out by the first words.

I've got a Shure SE30 I picked up at a flea market that I need to check out.

[seth.wagenman]

Ok so it has been over a decade since the last post on this. I think I will start a new post unless someone can definitively state that technology change has not made all of these suggestions obsolete.