Friday, October 8, 2010

Barnraising: Day 2

(Posted *way* late. Sorry, I got busy. *g*)

Day 2 of the barnraising began with me trying to find all the web streaming equipment that had been scavenged to do the stream from the Cannonball Room. This did not go very quickly, so the streaming for some of the workshops got started late. The streaming happened, though, so I must count that as a success. :)

By the time I'd finished getting all the streaming going, I'd missed most of the morning workshop session, so I didn't get to finish the tiny transmitter I'd been working on the day before. That's all right, though - I can build my own when I get home. I bet I can even adapt the design to broadcast on ham frequencies - maybe have my own little 70-centimeter or 2-meter transceiver.

I was going to go over to the station and help out there after the morning workshop session. Instead I spent some time checking on the web streaming. When I went in to check on the streaming in the workshop about recruiting volunteers and preventing burnout, I was immediately handed a slip of paper informing me that I was an octogenerian stockbroker who loved to dance. This was a role-playing exercise, you see, where some of us were potential volunteers and some of us were people trying to recruit volunteers. I played along, stayed for a bit of discussion, then wandered off to see what else was going on.

One interesting feature of the barnraising was the interview booth. The idea is that two people go into the booth and one of them interviews the other. The other then returns the favor. A volunteer staffer is also in the booth, and they record the interview, along with a couple of station ID's, for later broadcast. So I and a pretty girl named Meghan went in, and she interviewed me. I talked about why I'd come to the barnraising, and how I was trying to move away from IT and into broadcast engineering, and what got me into radio in the first place (a subject that I should perhaps elaborate upon in another post). I even briefly mentioned my days as Uncle Squishy, the host of the WEFT children's music show. (Uncle Squishy later reappeared as the occasional host of one of my WEFT overnight shows).

What with one thing and another, I didn't get over to the station until after lunch. I helped Sakura from Prometheus set the levels on the board, hung out while a carpenter was drilling holes for cables, and helped design a set of shelves to hold equipment until such time as a rack was obtained for said equipment.

Let me briefly describe the way we set the levels on the board. This may well not be industry standard, but once WGXC goes on the air, they can always adjust them again.

To start with, all the faders on the board were set to the same point. The reason we did that was to try and make sure that two given pieces of equipment would have roughly the same perceived volume when the faders on their respective channels were at the same point. When you've got a radio station, you don't want to have to remember that having the fader, say, halfway up on the CD player is fine, but having the fader halfway up on a microphone is *way* too quiet.

Using a Behringer cable tester, we generated a test signal. This signal could be set at three preset levels (i.e. volume) - one for microphones, one for consumer-grade equipment, and one for professional-grade equipment. For each channel on the board, then, we chose the appropriate level and ran it into the board. We then adjusted the trim pots - which are these tiny potentiometers (i.e. a variable resistor, often used to control volume) that you use to adjust the levels on a particular channel. Remember what I said above about having all the equipment being at the same volume for the same fader position? The trim pots are what you use to make that happen. In the case of the six (there are three physical mic modules, but each module on that board takes an "A" and a "B" input that you can switch between) microphone channels on the board, we only adjusted one pot each, because microphones are mono devices. For everything else, we adjusted the left and right pots separately. We set each channel so that with the fader about a quarter of the way up, the VU meter was near +11.

I left for dinner, and when I came back, I made a couple of XLR cables and helped run wiring in the studio. I really like the way their board does things - it's an Arrakis MARC-15. The neat thing about the MARC-15 is that the A & B inputs on each channel are RJ45. They're not Ethernet, though - it's not an IP console. Instead, the pins on the RJ45 are wired such that you can fit two balanced audio channels and a contact closure relay (a dingus that shorts two electrical wires, often used for start/stop control of attached audio devices) onto one jack. I like this idea. If you do it right - only have the wires going to your connectors be a few inches long, and the rest of the wires be contained in the Cat5 sleeve - it keeps the wiring very clean and compact. I'm on a plane right now, otherwise I'd post a picture.

Once things wrapped up at the studio, I made my way back to St. Mary's Academy and helped clean up, then went back to the Youth Center to sleep.

1 A VU meter (VU for "Volume Unit") is a thing on a console that tells you, effectively, how loud your broadcast is. It's an analog thing with a needle. The ranges vary from meter to meter, I expect, but I think the one on the WGXC board went from -10 to +3. That's probably a logarithmic scale.

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