At 11:50 AM 9/25/2005, David Lennick wrote:
>[log in to unmask] wrote:
>
> > In a message dated 9/23/2005 5:27:38 PM Eastern Daylight Time,
> > [log in to unmask] writes:
> > I had John French make me a 4-channel 8-track head assembly for my
> > "FrankenSony" pair of APR-5003V recorders that lets me play four
> > tracks simultaneously. The really neat thing about this head is that
> > I have infinite height adjustment without changing the head azimuth
> > or zenith, so I can tease out any track snippets as long as they are
> > at least 0.021 inches wide (or have adjacent silence totalling that
> > dimension).
> > ***********
> >
> > I've used a similar technique to recover the "center" track from some paper
> > based tapes that had been recorded on a Brush "Sound Mirror" then 
> reused on a
> > two track machine.
> >
> > It is very useful to be able to probe old tapes for hidden recordings or to
> > eliminate artifacts of badly aligned recorders.
> >
> > Mike Csontos
>
>This is worth knowing....we had a full-track Utah recorder from 1950, and
>beginning around 1959 the family (with me as an unwitting accomplice in the
>crime, since I wasn't old enough to protest) copied these tapes onto the newer
>Wollensak half-track at slower speed and then used the older tapes. 
>One of these
>years I'm going to want to try and get at the original recordings 
>still down the
>centre of the tapes, since the dubs were not very good.

Hi, David,

This technique is _very_ dependent upon the width of the erase head 
on the Wollensak. We know that the record heads are approximately 82 
mils wide, but the erase head can be anywhere up to 125 mils wide. At 
http://www.richardhess.com/tape/tips.htm I have different erase heads 
from pro machines.

I suspect that the Wollensak erase head is probably narrower than the 
pro heads pictured.

Perhaps a better head to use than the 21 mil tracks of the 8-track 
head is my NAB Stereo Cartridge head which has three 43 mil tracks, 
one is in the centre.

The wider track width still shouldn't get into the audio 82+82+43 = 
207, leaving 20 mil guard bands on either side of the centre track 
and the NAB 2-tracks. If it worked without crosstalk, it would 
provide better signal to noise ratio than the 21 mil head.

Someone just gave me a "mail-A-voice" head which has a narrow, 
extended centre pole piece which might work if it doesn't shred the tape.

I'm curious about the history of Utah - was that a Canadian brand? 
They made both paper and plastic tape?

Cheers,

Richard


Richard L. Hess                           email: [log in to unmask]
Vignettes 
Media                           web:   http://www.richardhess.com/tape/
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