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Author Topic: Again check your power before gigs!!  (Read 7947 times)

Jonathan Johnson

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Re: Again check your power before gigs!!
« Reply #10 on: April 25, 2014, 04:12:25 pm »

Thanks for putting in a plug for the hobby.

Have you been making the trade-show circuits?
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Taylor Hall

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Re: Again check your power before gigs!!
« Reply #11 on: April 25, 2014, 04:15:45 pm »

It certainly has a bright future.

But the prospects can be pretty dim if precautions aren't taken.

You could very easily be screwed.

Just be sure you can make a switch on a moment's notice.

And be sure not to trip your lucky break.

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BobWitte

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Re: Again check your power before gigs!!
« Reply #12 on: April 25, 2014, 04:25:12 pm »

Well, that started a flow of puns. Hopefully not many readers will revolt from this thread. Not sure how to gauge these though. We might meet with some resistance if we keep conducting ourselves like this. Time for me to switch off.


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Jonathan Johnson

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Re: Again check your power before gigs!!
« Reply #13 on: April 25, 2014, 04:42:50 pm »

Obligatory...
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Michael A. Yates

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Re: Again check your power before gigs!!
« Reply #14 on: April 27, 2014, 10:43:29 am »


So that implies that somewhere in that building is another outlet that is at 195 volts.  perhaps the one near where you want your powered speaker.

 How did you figure that? The electrical guys that came in said that's impossible... But I don't know if they really know what they are talking about?


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Kevin Graf

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Re: Again check your power before gigs!!
« Reply #15 on: April 27, 2014, 10:56:01 am »

A 'lost neutral' connection can cause the 120V circuits to divide the 240V in strange ways. 80V/160V or maybe 135V/105V depending on the load on each 120V leg.
But unconnected wires can also have weird voltage reading that are called phantom voltages. (very different from mic power phantom voltage)
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John Roberts {JR}

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Re: Again check your power before gigs!!
« Reply #16 on: April 27, 2014, 11:34:49 am »

A 'lost neutral' connection can cause the 120V circuits to divide the 240V in strange ways. 80V/160V or maybe 135V/105V depending on the load on each 120V leg.
But unconnected wires can also have weird voltage reading that are called phantom voltages. (very different from mic power phantom voltage)
+1... 45V feeding a 100W light bulb, is different than 45V reading on a high impedance voltmeter.

But both are wrong.

JR
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Mike Sokol

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Re: Again check your power before gigs!!
« Reply #17 on: April 27, 2014, 12:07:26 pm »

+1... 45V feeding a 100W light bulb, is different than 45V reading on a high impedance voltmeter.

But both are wrong.

JR

+2... These so called "phantom" voltages are typically capacitively coupled by proximity to live wires, thus creating a high-pass crossover circuit of sorts. That's why these phantom voltages often sound like a high-frequency buzz rather than a low-frequency hum. If it was a solid connection there would be hum and a lot more current carrying ability. But this undesired capacitor coupling doesn't let the bass (60 Hz) through, only the higher harmonics.

You get the same sort of effect when you have an open leg on a mic line. You'll probably notice that the signal level will drop way down, and all that's left is high frequencies. That's because there's capacitive coupling of the broken leg wire to the shield which creates a high-pass filter tilt on the signal coming into the balanced input.   
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Mike Sokol
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Re: Again check your power before gigs!!
« Reply #17 on: April 27, 2014, 12:07:26 pm »


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