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#1
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Is there a device or software that i can use to measure the voltage passsing
between two points and record that somehow, over a time period of say, a month? Cheaper would be better. Here's why I need such a thing. The Calrec Sigma console I use at work is intermittently making a loud Digital kind of Zapping noise, like when your Converters totally wack out for a second. And if I touch the touch sensitive faders say a second later I get a strong electric shock, which on next retouching is gone. This has also happened when i have *already* had my hand sitting on one the faders, so the explanation of "static electricity" - at least as we commonly think of it - does not make sense. It also has happened in quite humid times of year, not just when the air is dry as is typical for static. The first time this happened my A2 was plugging in a hardline mic at the time. We have mic direct outs from the Calrec feeding a PA MIxer on the Studio floor, incorrectly patched into mic inputs. When I got the first shock I went down to that PA Mixer and found Phantom power was engaged on some console channels, and I assumed that as this was feeding multiple channels of 48V back up into the output busses of the Calrec that this accounted for the shock - yeah I know, they have diodes and blocking caps in there for protection, but it seemed to happen at the same time. However I have since been shocked and heard the noise bursts with the PA mixer totally shut off, this has happened about 12 times since August. The Studio D/Control facility is first class in terms of design, Chris Bauer our former Director of Engineering is no slouch (and his Dad was an original "Harmonicat"), and all is according to Calrec's specs for the mixer installation (except for how the PA Board is interfaced, there the facility Install guys ignored my warnings about how that shouild be done. Hey, XLR - XLR!) Anyway everything is well tied to heavy copper buss bars tied to a star ground buss bar, tied to the building. The Calrec's Control surface and Audio rack have separate power supplies. I would like to record the voltages passing between say, one of the Calrec's faders and a ground point for a month and see it we get any spikes, and record the time, duration and voltage of any events. I would like to record and quantify this mystery. I am concerned this could be a Console manufacturing defect or design problem obviously, but one of the construction guys who physically built the room made an interesting comment. He said "The room is built for Static electricity. When we were building it we were getting strong shocks *from the building* and called in electricians, and they said it was just static." Now there were once defects in some of the Robo Cam pedestal that caused them to spit garbage into the BSP panels they shared with our mic inputs throuigh the common grounds, making our mics "pop", and I am wondering if it is possible that something similar is happening? Although there are shocks involved here, so is there any way that might make sense? Maybe there sometimes such a different potential between the studio floor and the control room that there are current spikes through the patchbay ties? Could bad lighting dimmers electrify our BSP panels mometarily through the grounds, or if there was a short between a ground wire and pin 2 on a mic connection would that allow a potential in somewhere it should not go? This is a hard one to nail down, especially for a guy who is mainly a mixing engineer such as I, and it is such a transient event. Ideas anyone? Thanks. Will Miho NY Music & TV Audio Guy Audio Guy / Fox News "The large print giveth and the small print taketh away..." Tom Waits |
#2
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I think i saw a Fluke that has a tape read out. I'm not sure funtions
were available on that. There is a test setup that is an external box that runs off a PC. I forget what it's called. It will generate everything from bars to squarewaves, and read like a scope into whatever computer. Might be a bit excessive to track down an intermitant. Does the Control surface of the Sigma 100 send a multi-pair of just Coax back to the frame. We put in a Euphonix at Food Network and because the frame was in the machine room we had to lift a pin in the EDACs that take control from the surface back to the frame. Your Circuit should all be on a major UPS, like most TV stations. Make sure no-one has plugged into a technical ground outlet on that leg with anything that shouldn't be in there. Definately check the electrical system. ( what panel gets what circuit ; are the grounds continuos ) |
#3
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WillStG wrote:
I would like to record the voltages passing between say, one of the Calrec's faders and a ground point for a month and see it we get any spikes, and record the time, duration and voltage of any events. I would like to record and quantify this mystery. Chart recorders are the old traditional way of doing this, but you will find a lot of the power loggers will let you measure DC voltages as well over the long term. The Fluke power loggers are probably rentable from some place like Tucker that rents test equipment. Astro-Med makes some loggers that pretend to be chart recorders with LCD displays. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#4
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The cheap way is to just use a DVM with peak hold, one with no auto shut
off..... I have done this many times just hang it on the test points to capture the peak voltage when the fault occurs. If that will not work there are many instrumentation recorders with 0-5V or 0-20ma input which you can add resistors to for the desired range. Have a look at http://www.transcat.com/ for available recorders or give their sales types a call.... Rgds: Eric "WillStG" wrote in message ... Is there a device or software that i can use to measure the voltage passsing between two points and record that somehow, over a time period of say, a month? Cheaper would be better. Here's why I need such a thing. The Calrec Sigma console I use at work is intermittently making a loud Digital kind of Zapping noise, like when your Converters totally wack out for a second. And if I touch the touch sensitive faders say a second later I get a strong electric shock, which on next retouching is gone. This has also happened when i have *already* had my hand sitting on one the faders, so the explanation of "static electricity" - at least as we commonly think of it - does not make sense. It also has happened in quite humid times of year, not just when the air is dry as is typical for static. The first time this happened my A2 was plugging in a hardline mic at the time. We have mic direct outs from the Calrec feeding a PA MIxer on the Studio floor, incorrectly patched into mic inputs. When I got the first shock I went down to that PA Mixer and found Phantom power was engaged on some console channels, and I assumed that as this was feeding multiple channels of 48V back up into the output busses of the Calrec that this accounted for the shock - yeah I know, they have diodes and blocking caps in there for protection, but it seemed to happen at the same time. However I have since been shocked and heard the noise bursts with the PA mixer totally shut off, this has happened about 12 times since August. The Studio D/Control facility is first class in terms of design, Chris Bauer our former Director of Engineering is no slouch (and his Dad was an original "Harmonicat"), and all is according to Calrec's specs for the mixer installation (except for how the PA Board is interfaced, there the facility Install guys ignored my warnings about how that shouild be done. Hey, XLR - XLR!) Anyway everything is well tied to heavy copper buss bars tied to a star ground buss bar, tied to the building. The Calrec's Control surface and Audio rack have separate power supplies. I would like to record the voltages passing between say, one of the Calrec's faders and a ground point for a month and see it we get any spikes, and record the time, duration and voltage of any events. I would like to record and quantify this mystery. I am concerned this could be a Console manufacturing defect or design problem obviously, but one of the construction guys who physically built the room made an interesting comment. He said "The room is built for Static electricity. When we were building it we were getting strong shocks *from the building* and called in electricians, and they said it was just static." Now there were once defects in some of the Robo Cam pedestal that caused them to spit garbage into the BSP panels they shared with our mic inputs throuigh the common grounds, making our mics "pop", and I am wondering if it is possible that something similar is happening? Although there are shocks involved here, so is there any way that might make sense? Maybe there sometimes such a different potential between the studio floor and the control room that there are current spikes through the patchbay ties? Could bad lighting dimmers electrify our BSP panels mometarily through the grounds, or if there was a short between a ground wire and pin 2 on a mic connection would that allow a potential in somewhere it should not go? This is a hard one to nail down, especially for a guy who is mainly a mixing engineer such as I, and it is such a transient event. Ideas anyone? Thanks. Will Miho NY Music & TV Audio Guy Audio Guy / Fox News "The large print giveth and the small print taketh away..." Tom Waits |
#5
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Eric K. Weber wrote:
The cheap way is to just use a DVM with peak hold, one with no auto shut off..... Like the Fluke 12's I use for routine troubleshooting. They have a 100-hour min/max memory, so you can tell when the event(s) happened. |
#6
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Thanks one and all.
They did put in an antistatic mat, but as this has happened even when I had had my hand sitting on the fader for some time already I don't expect that to solve the matter, although it might keep me from feeling the current present. I'll see if I can borrow a DMM from engineering, and check out Fluke's devices. Will Miho NY Music and TV Audio Guy Staff Audio / Fox News "The large print giveth and the fine print taketh away..." Tom Waits |
#7
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"WillStG" wrote ...
Is there a device or software that i can use to measure the voltage passsing between two points and record that somehow, over a time period of say, a month? Cheaper would be better. Here's why I need such a thing. The Calrec Sigma console I use at work is intermittently making a loud Digital kind of Zapping noise, like when your Converters totally wack out for a second. Several digital DMMs have logging features, even low-price ones. However, note that if you are looking for short-duration transient phenomenon, you might need a higher sampling-rate than they provide to capture your transient. Test equipment rental places will have several different kinds of units specifically made to monitor various things and record any anomalies. Most of them are designed for monitoring power line issues. The Studio D/Control facility is first class in terms of design, Chris Bauer our former Director of Engineering is no slouch (and his Dad was an original "Harmonicat"), and all is according to Calrec's specs for the mixer installation (except for how the PA Board is interfaced, there the facility Install guys ignored my warnings about how that shouild be done. Hey, XLR - XLR!) Anyway everything is well tied to heavy copper buss bars tied to a star ground buss bar, tied to the building. The Calrec's Control surface and Audio rack have separate power supplies. But remember that design and execution are two different things. The very best design is of only academic interest in the absense of appropriate execution. And top-notch electricians doing the installation still make errors occasionally. I would like to record the voltages passing between say, one of the Calrec's faders and a ground point for a month and see it we get any spikes, and record the time, duration and voltage of any events. I would like to record and quantify this mystery. Are these two items supposed to be connected together already? If not, why not? You might be better off measuring continuity between them while you exercise connectors and wiring to see if there is an intermittent. I am concerned this could be a Console manufacturing defect or design problem obviously, but one of the construction guys who physically built the room made an interesting comment. He said "The room is built for Static electricity. When we were building it we were getting strong shocks *from the building* and called in electricians, and they said it was just static." I have read about issues with metal-frame high-rise buildings where different parts of the metal infrastructure weren't exactly electrically bonded together as one would expect. Even here in this newsgroup I think I remember someone reporting that they abandoned their original location of a studio because they could never get rid of the RFI and other problems. But moving across the hall (or up a floor?) worked out just fine. Who knows why these things happen? But who has the time/resources to figure it out either? |
#8
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Do you have carpet on the floors? You might want to consider carpet made
for computer machine rooms, which has conductive fibers for anti static AATCC 134... ..... Sounds like static with the metal part of the fader which the knob is attached to arcing over to the wiper of the potentiometer...... Some static grounding issues in the console / fader design and possibly a poor choice of flooring / seating material... The BASF web site suggests 3500 Volts of static electricity is required to feel the spark...... this would certainly overload the a/d converters if it arced to the wiper of the fader..... Rgds: Eric "WillStG" wrote in message ... Is there a device or software that i can use to measure the voltage passsing between two points and record that somehow, over a time period of say, a month? Cheaper would be better. Here's why I need such a thing. The Calrec Sigma console I use at work is intermittently making a loud Digital kind of Zapping noise, like when your Converters totally wack out for a second. And if I touch the touch sensitive faders say a second later I get a strong electric shock, which on next retouching is gone. This has also happened when i have *already* had my hand sitting on one the faders, so the explanation of "static electricity" - at least as we commonly think of it - does not make sense. It also has happened in quite humid times of year, not just when the air is dry as is typical for static. The first time this happened my A2 was plugging in a hardline mic at the time. We have mic direct outs from the Calrec feeding a PA MIxer on the Studio floor, incorrectly patched into mic inputs. When I got the first shock I went down to that PA Mixer and found Phantom power was engaged on some console channels, and I assumed that as this was feeding multiple channels of 48V back up into the output busses of the Calrec that this accounted for the shock - yeah I know, they have diodes and blocking caps in there for protection, but it seemed to happen at the same time. However I have since been shocked and heard the noise bursts with the PA mixer totally shut off, this has happened about 12 times since August. The Studio D/Control facility is first class in terms of design, Chris Bauer our former Director of Engineering is no slouch (and his Dad was an original "Harmonicat"), and all is according to Calrec's specs for the mixer installation (except for how the PA Board is interfaced, there the facility Install guys ignored my warnings about how that shouild be done. Hey, XLR - XLR!) Anyway everything is well tied to heavy copper buss bars tied to a star ground buss bar, tied to the building. The Calrec's Control surface and Audio rack have separate power supplies. I would like to record the voltages passing between say, one of the Calrec's faders and a ground point for a month and see it we get any spikes, and record the time, duration and voltage of any events. I would like to record and quantify this mystery. I am concerned this could be a Console manufacturing defect or design problem obviously, but one of the construction guys who physically built the room made an interesting comment. He said "The room is built for Static electricity. When we were building it we were getting strong shocks *from the building* and called in electricians, and they said it was just static." Now there were once defects in some of the Robo Cam pedestal that caused them to spit garbage into the BSP panels they shared with our mic inputs throuigh the common grounds, making our mics "pop", and I am wondering if it is possible that something similar is happening? Although there are shocks involved here, so is there any way that might make sense? Maybe there sometimes such a different potential between the studio floor and the control room that there are current spikes through the patchbay ties? Could bad lighting dimmers electrify our BSP panels mometarily through the grounds, or if there was a short between a ground wire and pin 2 on a mic connection would that allow a potential in somewhere it should not go? This is a hard one to nail down, especially for a guy who is mainly a mixing engineer such as I, and it is such a transient event. Ideas anyone? Thanks. Will Miho NY Music & TV Audio Guy Audio Guy / Fox News "The large print giveth and the small print taketh away..." Tom Waits |
#9
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Eric K. Weber wrote:
Do you have carpet on the floors? You might want to consider carpet made for computer machine rooms, which has conductive fibers for anti static AATCC 134... Non-static floormatting is also worth checking out, and as a temporary measure anti-static sprays will help. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
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