Demagnetizing mishap

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Victory Pete

Victory Pete

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Has anyone ever had the power go out while you were demagnetizing? There are so many warnings about not turning off the demagnetizer while near the heads that I am afraid the power might go off someday. I have been thinking about this for years. Recently there has been a lot of power glitches. I am considering using a UPS for demagnetizing. I found an APC unit that is true sinewave. My friend has a Furman but we looked at the waveform with an oscilloscope and was horrified, looked like a trainwreck.
VP:eek:
 
It's like a 1 minute procedure...what are the odds you will lose power...?
 
Victory Pete said:
Has anyone ever had the power go out while you were demagnetizing? There are so many warnings about not turning off the demagnetizer while near the heads that I am afraid the power might go off someday. I have been thinking about this for years. Recently there has been a lot of power glitches. I am considering using a UPS for demagnetizing. I found an APC unit that is true sinewave. My friend has a Furman but we looked at the waveform with an oscilloscope and was horrified, looked like a trainwreck.
VP:eek:
Click to expand...
I think that it would simply mean you'd have to start the demagnetizing process over again.
Unless I'm mistaken ...... turning off the power while close to the heads can impart some magnetism to the heads. That's the reason you demagnetize in the first place so it seems that you'd just have to demagnetize again from the beginning.
 
I've thought of that too...yes the odds are slim but the stakes are high because if the degausser is close to the heads wen the power goes out they will be permanently magnetized...toast. That's why a degausser should never have a power switch because it is crucial that it doesn't turn off until it is a safe distance from the headblock...power switch would make it too easy to make a tragic mistake.

Why does it matter if the degausser gets clean power?
 
Lt. Bob said:
I think that it would simply mean you'd have to start the demagnetizing process over again.
Unless I'm mistaken ...... turning off the power while close to the heads can impart some magnetism to the heads. That's the reason you demagnetize in the first place so it seems that you'd just have to demagnetize again from the beginning.
Click to expand...

What he is worried about is that you should not turn off when close because the demag can spike and leave a higher-than-normal amount of magnetism that the demag will then not be able to remove.

However, there is a school of thought that says that is not so, and there is NO spike, that it actually just falls off to zero...so that in reality, you CAN turn it off as close as 6 inches away.

Here's more info from MRL:

http://home.comcast.net/~mrltapes/mcknight_demag.pdf

Read on page 3 the section about "Magnetizing and Demagnetizing"...it points out that there is NO spike in the magnetic field (it falls to zero), there is a spike only the output voltage, which will have no effect on your heads or cause them to be magnetized.

So...I guess it doesn't matter about the power going out while magnetizing. :)
 
I've had it happen to me where the demag went off while in use on the heads. I simply got it powered up again and proceeded with a very slow and long demagnatizing and the recorder was none the worse for it.
 
Lance Lawson said:
I've had it happen to me where the demag went off while in use on the heads. I simply got it powered up again and proceeded with a very slow and long demagnatizing and the recorder was none the worse for it.
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What caused it to go off? What model was it?
VP
 
About 2 years ago when i first got my Tascam 38, my brain wasn't in the right place that day and i had my machine on, forgot to shut it off, cleaned my pinch roller, then powered up the demagnitizer, got it close to the heads, all the VU meters went up for a split second. I pulled it away and shut it off. I almost had a heart attack as I thought i just destroyed the heads. Thank god, my machine and the heads still worked fine and sounded great.. See what happens when you aren't thinking.
 
I'm somewhat paranoid when demaging my 38. I unplug it to make sure it can't power up. Might be a little extreme, but I'd rather do that then replace parts.
 
dodgeaspen said:
I'm somewhat paranoid when demaging my 38. I unplug it to make sure it can't power up. Might be a little extreme, but I'd rather do that then replace parts.
Click to expand...

I know, I am always nervous about wrecking something by being careless. I have had a lot of regretable incidents that happen in the heat of recording my own masterpiece, with beer! They end up as a messapiece!
VP:eek:
 
I plug into a UPS... just an old APC 700.

It's a good question and for years I never gave it much thought even though I knew and still believe it can leave the head polarized in one way or the other, depending on where the cycle was when it lost power. Losing power is the same as suddenly yanking the degausser away rather than slowly moving it away.

If the degausser is close enough to the head to be degaussing then it's close enough to the head to leave it polarized if power is lost.

Just use the "When in doubt" rule. Extra precaution doesn't hurt. Plus once you invest in a UPS the power will never go out… trust me.

I designed and built a whole-house UPS system with a heavy-duty inverter and enough batteries to power essentials for three days.

becksbox.jpg


And now I'll be damned if I can get the power to go off. Now I want it to go off so I can bask in the glow of my creation. I'll be in the front yard in a thunderstorm during a tornado warning shaking my fist to the sky and screaming. "C'mon! Is that all you got? Is that all you can do?" Just like Lt. Dan in the movie Forrest Gump. (No I'm not kidding)

for%20a%20dan.jpg


Same thing happened when I bought a 4-wheel drive Chevy Blazer years ago. It stopped snowing in these parts during winter. I threatened to move someplace else where there was a little more man against nature action... the Dakotas maybe.

I need some battles to feel alive. Watching my savings dwindle away in this economy helps a little, but it's really not the same sort of thrill. Once I lose everything and am living off the land deep in Shawnee National Forest I’ll probably be pretty content. Just me and you and a dog named Boo... and a guitar... maybe a pan flute.

So yeah… I mean… don’t you think we should get points for word count rather Than just post count? :)
 
Beck said:
I plug into a UPS... just an old APC 700.

It's a good question and for years I never gave it much thought even though I knew and still believe it can leave the head polarized in one way or the other, depending on where the cycle was when it lost power. Losing power is the same as suddenly yanking the degausser away rather than slowly moving it away.

If the degausser is close enough to the head to be degaussing then it's close enough to the head to leave it polarized if power is lost.

Just use the "When in doubt" rule. Extra precaution doesn't hurt. Plus once you invest in a UPS the power will never go out… trust me.

I designed and built a whole-house UPS system with a heavy-duty inverter and enough batteries to power essentials for three days.

becksbox.jpg


And now I'll be damned if I can get the power to go off. Now I want it to go off so I can bask in the glow of my creation. I'll be in the front yard in a thunderstorm during a tornado warning shaking my fist to the sky and screaming. "C'mon! Is that all you got? Is that all you can do?" Just like Lt. Dan in the movie Forrest Gump. (No I'm not kidding)

for%20a%20dan.jpg


Same thing happened when I bought a 4-wheel drive Chevy Blazer years ago. It stopped snowing in these parts during winter. I threatened to move someplace else where there was a little more man against nature action... the Dakotas maybe.

I need some battles to feel alive. Watching my savings dwindle away in this economy helps a little, but it's really not the same sort of thrill. Once I lose everything and am living off the land deep in Shawnee National Forest I’ll probably be pretty content. Just me and you and a dog named Boo... and a guitar... maybe a pan flute.

So yeah… I mean… don’t you think we should get points for word count rather Than just post count? :)
Click to expand...

Is that a Faraday shield I see around those batteries?
VP
 
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