At 09:54 AM 2/2/2003 -0200, you wrote:
>As I mentioned in my earlier posting, by connecting my analogue recorder to
>my DAT recorder and the latter to the sound card I now transfer recordings
>to the computer in a single step. However, sometimes a mysterious loud hum
>appeared in the sound file. This turned out to be caused by my switching on
>a halogen desk light whose transformer happened to be right next to the
>analogue recorder.
>
>Jeremy
Jeremy:
I have rediscovered this fact now several times over the years. Of course
cassettes and R-R tape machines generate the audio signal by passing tape
over a pickup designed like a transformer with a narrow open magnetic gap.
So I, too, have found a desk florescent light to be my main enemy in
digitizing old tapes. Any power transformer within 2 meters potentially
can provide magnetic (and therefor un-shieldable) hum in the recordings.
my best regards,
Marty Michener
MIST Software Associates PO Box 269, Hollis, NH 03049
EnjoyBirds.com - Software that migrates with you. http://www.EnjoyBirds.com
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