RE: [AV Media Matters] Spring Wound Tape Recorder

[Jim Lindner <jim@vidipax.com>]

The VidiPax museum does have this machine in it's collection along with
MANY others. If visiting New York City - please feel free to stop by and
see some of our technoogy history!!

jim

m.biel@morehead-st.edu wrote:
>A friend of mine in Ljubljana, Slovenia is looking for information
>about a tape recorder which was used by his ethnomusicalogical
>archive in the 1950s.  They would really like a schematic and a copy
>of the instruction manual. It is the Magnemite Portable, model
>610-C, made by the Amplifier Corp. of America, New York,  serial
>number: 3703
>
>It is an unusual machine in that it is spring wound.  I remember
>seeing it in the annual tape recorder directories that AudioDevices
>published in the early 60s, but have no other print info.  The
>archive received it from a group of Slovenian expats in the US
>around 1956.  It is about the size of a Nagra, uses 7-inch reels of
>quarter inch tape, the electronics runs only off of 4.5 volt and 90
>volt battery power, and the motor is spring wound.  The main visual
>feature of the machine as pictured in the recorder guide is a large
>spoked-wheel on top which I had always thought was the spring
>winding mechanism.  It actually is a removable flywheel for the
>capstan.  Erasure is done by a rotatable permanent magnet--you had
>better remember to rotate it away from the tape path when not
>recording!!!
>
>We had a chance to inspect and operate the mechanics of the machine
>a few months ago in Slovenia.  The machine threads backwards
>compared to most machines.  To allow the tape to be played on any
>standard half-track machine, the lower half of the tape is recorded
>because the tape runs from the right to left reels from the outside
>back towards the outside back.  Thus the reels and the capstan all
>rotate clockwise.  Think about it folks, why would a tape recorder
>have these things rotating clockwise???  It is because the motor is
>a PHONOGRAPH motor!!  We didn't have a strobe disc handy, but it
>seemed to me that the capstan was rotating at 78!  We located a
>screwdriver speed adjustment on the flying-ball governor--but didn't
>touch it, of course.  We are curious if the instruction manual had
>you adjust the speed with a phonograph strobe disc.  If so, consider
>the fact that in 60 cycle territory--where the machine was built--78
>is actually 78.26, but in 50 cycle territory the speed is 77.91.
>Using a strobe disc in Europe would result in too slow a tape
>speed.
>
>If any of you have any data on this machine--or have one--let me
>know.
>
>Mike Biel  m.biel@morehead-st.edu

Jim Lindner - President
VidiPax - The Magnetic Media and Information Migration Full Services
Company
Telephone 212-563-1999
www.vidipax.com
Moderator of A/V Media Matters@topica.com