AC Distribution in an Equipment Box

Stevens R. Miller

Well-Known Member
My community theater company apparently had a custom equipment box made for their eight Shure wireless microphone receivers and their Behringer mixer. The box weighs a ton and the wiring involves a pair of one-to-three AC adapters plugged into an AC power strip. I'm thinking there's a better way to move and store this equipment. In particular, I'd like advice and thoughts on how the AC is distributed in the current setup, and suggestions for improvement. A picture of the current arrangement is attached to this post.

Thanks!
 

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Amiers

Renting to Corporate One Fixture at a Time.
It doesn't look horrible. I would be more worried about a ground loop happening more than anything.
If it isn't drawing more than it should I wouldn't worry to much.
 

BillConnerFASTC

Well-Known Member
If it's weight, what about casters? Or just a dolly or hand truck to move it?

Wiring does not look so bad. Probably would prefer a single plug strip with more outlets and delete the cube taps, which probably violate some little enforced code issue.
 

JD

Well-Known Member
There's really not a clean way with those receiver adapters. Have the same problem with the Sennheisers, with the addition of the fact that the adapter is part of the plug. (wallwart)
I am surprised that you're getting clean reception with all the antennas buried in the box like that.
 

Stevens R. Miller

Well-Known Member
Wiring does not look so bad. Probably would prefer a single plug strip with more outlets and delete the cube taps, which probably violate some little enforced code issue.
Probably more than one. It is a fire-code violation to plug a power-strip into another power-strip. People do this all the time and the fire-police don't come busting down your door. But, in commercial environments, a spot-check from a fire-marshall can get you dinged for it. So, not only are those cubes a violation by being plugged into a strip, that strip invites its own violation because it tends to be plugged into another strip outside the box.

Now, I'm not too squeamish about these sorts of things, but those fire codes do exist for a reason. In a top-of-the-line product, what would one see used for AC distribution in an enclosure like this?
 
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Stevens R. Miller

Well-Known Member
I am surprised that you're getting clean reception with all the antennas buried in the box like that.
Yeah, that's another topic. My preferences would be these:

1. Mount the antennas in the wings and run coax to the receivers.
2. At least move the antennas out of the box with short pieces of coax and keep them near the box, but a half-wavelength apart, as measured from center stage.
3. Replace those sixteen stubby antennas with two log-periodic directionals and (if necessary) a signal pre-amp to drive all eight receivers with a lot less hardware.
4. Get the actors to do their jobs and raise their voices like actors were doing for centuries before we started spending a thousand dollars a pop on these things. (Maybe this one is actually higher than Number Four on my list of preferences, but one must be realistic.)

I'm pretty good with radio, less so on electronics in general, and know very little about handling electric power. But, I'm about all the "engineer" this company has and they are slowly developing some faith in my recommendations. With any luck, they'll let me do something from the list above, but that's going to have to wait for another day. In the meantime, I'm kind of anxious about all those plugs...
 

Amiers

Renting to Corporate One Fixture at a Time.
Well you could add this to your rack if it will fit.

https://www.bhphotovideo.com/bnh/controller/home?O=&sku=1011786&gclid=Cj0KEQjwzd3GBRDks7SYuNHi3JEBEiQAIm6EI7QGHqlsuGqBo21-Zoi2upiOZ9_2-jvChHs2qTHX2ngaAjoE8P8HAQ&is=REG&ap=y&m=Y&c3api=1876,{creative},{keyword}&A=details&Q=

It will add more weight though so maybe it's not what you are looking at. I counted 9 things plugged in less I'm missing something.

The only way you are going to cut the weight is split it into 2 racks.

Edit: Seems I didn't scroll up, that would work as well
 
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Stevens R. Miller

Well-Known Member

That looks pretty good and we do have a 1U gap still open in the front of the box.

It will add more weight though so maybe it's not what you are looking at. I counted 9 things plugged in less I'm missing something.

Nope, you're not missing anything. Eight receivers and the mixer.

The only way you are going to cut the weight is split it into 2 racks.

Well, I haven't seen much of this kind of stuff, but the box is built like a brick outhouse. The mixer is just a few pounds (I had to take it out to fix something inside it). The receivers are each pretty light. But the box is made of dense plywood and metal fixtures. I'd wager well over half of its total weight is just the box. What's worse, whomever made it decided it would only need two handles, each dead-center on the left and right sides, below the center of gravity. Thus, when you (and a friend) pick it up, it wants to flip over. It really should have had four handles on it, for easier lifting and stability.

Is plywood common for these things? It seems like overkill, to me.
 

JD

Well-Known Member
Ahhh! Possibly a Chinese box? I have seen a lot of Anvil knock-offs that look good but weigh a ton! The true Anvil cases have found the perfect balance between weight and strength. I had ordered in one of those Chinese alternatives for a mixer and equalizer and when it arrived it felt like it already had a 40 pound power amp mounted in it! Upon examination, the wood was 1/2 inch thick! Yea, great protection for everything except my back! Your answer may be a different case, like something from Gator or Anvil. Lift before you buy ;)
 

KBToys82

Active Member
I would definitely get a distro-unit. Most will be able to plug 4 receivers into it as well as the 2 antenna's, thus saving you from the amount of plugs you take up in your power strip.
 

JD

Well-Known Member

Stevens R. Miller

Well-Known Member
You might want to copy and paste the text of that link. For some reason it gets hijacked.

That is really screwy. The HTML page source shows a perfectly normal href tag. But even if you copy the link address and paste that, it isn't what's in the HTML. I've never seen anything like that before.
 

Stevens R. Miller

Well-Known Member
Okay, it looks like ControlBooth has added something called "Viglink" that hot-swaps an intermediate URL in place of the one you are trying to reach (or, a virus has gotten onto CB that did the same thing). The intermediate link identifies ControlBooth as the sender, so CB probably gets some kind of advertising revenue from the folks boosted on the intermediate page. You can "opt out," which I am guessing puts a cookie into your browser, at this page: http://www.viglink.com/opt-out/

I'm not promising it's safe, but I risked it and it worked for me.
 

RonHebbard

Well-Known Member
Premium Member
Hey, that's pretty cool! Any idea why the antenna jacks are labeled with "12V DC?"
I haven't read this entire thread but if the question is 'why would there be 12 VDC on RF antennae input connectors' my answer would be to phantom power remote (or in-line) RF antennae pre-amps. I don't do much with wireless mics but I once was invited to troubleshoot someone's system and the problem wasn't too much audio gain but far too much RF gain. Figuratively speaking, a buzzing fly's worth of RF was overloading their RF front ends. Whoever put the system together used a diversity pair of phantom powered dipole antennae and when the coaxs from the two dipoles reached the rack they had an antenna preamp inserted in each lead before they hit the RF splitter inputs. With each powered dipole driving an inline pre-amp, the splitters two inputs were both totally overloaded with input signal. @FMEng can likely elaborate on this far better than I can. Basically I kept the two powered antennae as they were neatly installed and the pre-amps were part of the dipoles but I disconnected the two pre-amps within the rack and left them physically in place. Result: Less high-dollar electronics and a flawlessly functioning system no longer picking up the noise of architectural lighting fixtures firing up.
Toodleoo!
Ron Hebbard.
 

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