I do not do it nearly as often. I do it rigorously after assembling,
modifying, or acquiring a new head block and then maybe every 100 hours
for a particular head assembly.
Depending on the project, I may do it before a project.
I also tend to demagnetize the heads in a group when I have the
There was this discussion on, I think, one of the Studer lists about how
to test for demagnetization and it involves 15 or 20 kHz erasure more
than any other technique. I think we agreed that the magnetometer sold
with the Han-D-Mag kit is not terribly useful on tape heads.
One thing to remember is that the earth's DC magnetic field is about 0.5
Gauss at most points on the Earth.
On 2013-11-01 3:55 PM, John Schroth wrote:
> As standard practice, I usually demagnetize the heads on any tape deck
> at the start of each morning when I'm doing audiotape digitizing. But it
> occurred to me that it might be worth asking what others on the list do.
> How often do you demagnetize your heads if you're putting 6-8 hours on
> them a day? Do you demagnetize more or less often for different formats
> (such as cassette verses reel-to-reel)? Is there a measurement device
> that could tell you if your heads require demagnetization?
> Any input would be appreciated.
> John Schroth
-- Richard L. Hess email: [log in to unmask]
Aurora, Ontario, Canada 647 479 2800
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