Thank you, Bruce. It was inspired by a cylinder where there was a strong
foreground element and a weaker one which was still intelligible.
It was a homemade cylinder which was not properly shaved and some remnant
of the original groove was left. This to me was akin
to old manuscripts -- palimpsests -- where the surface was scraped off and
another surface applied, however some remnant of the
old inking is still visible and, through x-ray or other analysis, still
legible. And it refers to the resultant artifact rather than the process
that made it, which would tend to vary in recordings.
Uncle Dave Lewis
On Thu, Feb 28, 2013 at 11:53 AM, Gordon, Bruce <[log in to unmask]>wrote:
> The term 'partial erasure' could imply erasing only a part of the tape if
> you take it literally.
> 'Recording over insufficient erasure' might be more exact.
> I still like 'palimpsest' because it packs so much in so little space.
> Bruce J. Gordon
> Audio Engineer
> Audio Preservation Services
> Harvard University
> Cambridge, Massachusetts 02138
> tel. +1(617) 495-1241
> fax +1(617) 496-4636
> On Feb 25, 2013, at 5:31 PM, Henry Borchers <[log in to unmask]> wrote:
> > Thank you for all of your input and suggestions. I want to clarify
> > something. My problem is not print-through but what Richard Hess is
> > calling "partial erasure". After doing a little more research, I came
> > across the term "overwrite" on the A/V artifact atlas website
> > (http://preservation.bavc.org/artifactatlas/index.php/Overwrite). Part
> > my digitization work is research as I am writing documentation and
> > policies for passing digitization duties of this collection on to other
> > staff. The workflow isn't my problem, it's the proper description. What
> > I'm trying to do is match my documentation terminology to already
> > established names as I don't want to create names for terms that are
> > already defined.
> > Is there a single "proper term" for this? Both "Overwrite" and "partial
> > erasure" are exactly what I'm talking about and would like to know if
> > other people out there use these terms to describe this issue.
> > Thank you for all the insight.
> > --
> > Henry Borchers
> > Broadcast Media Digitization Librarian
> > University of Maryland
> > B0221D McKeldin Library
> > College Park, MD 20742
> > (301) 405-0725
> > On 2/25/13 4:17 PM, "Richard L. Hess" <[log in to unmask]> wrote:
> >> Hi, John,
> >> Thanks for the referral...
> >> There are many different causes for what Henry might be hearing. From
> >> his original posting, I would say that print-through is less likely than
> >> other causes, but it certainly is a point worth considering.
> >> Let's look at some of the issues:
> >> (a) Partial erasure--this is the worst in many ways as it can be totally
> >> unrecoverable. Partial erasure would occur if the erase head were
> >> disconnected or the erase circuitry was not putting out enough energy to
> >> fully erase the tape. That means that the two programs (original,
> >> unwanted AND new, wanted) are now completely mixed in the magnetic
> >> (b) Sloppy re-use of pre-recorded tape. Assuming everything is working
> >> fine, but you are using pre-recorded tape and starting and stopping
> >> recording, it is possible to leave gaps of the previous, unwanted
> >> program between start cycles of the new, desired recording. This is what
> >> at least some of the issues that Henry was describing sound like. Unless
> >> these are long and intelligible (from a content perspective) in their
> >> own right, I usually ignore them.
> >> (c) Track incompatibility between original and subsequent recording.
> >> Take, for example, a two-track stereo tape that has been recorded over
> >> with a quarter-track stereo recorder. Depending on the width and
> >> alignment of the quarter-track erase heads, there can still be narrow
> >> strips of perfect-condition original underlying recording existing on
> >> the tape. Here is where my 4-channel, 8-track custom made "elevator"
> >> head which retains azimuth as I scan any 17 mil segment of a tape comes
> >> in handy. This can also be the result of recording over a full-track
> >> tape with two-track or quarter-track new recordings. It is interesting
> >> to note that the Woelke two-track erase heads supplied by Studer and
> >> Sony on pro machines had no gap and erased the full-width of the tape.
> >> The erase heads for timecode machines, on the other hand, did not erase
> >> the tiny centre timecode track, leaving that function to an erase
> >> section of the timecode head. If a two-track tape was partially erased
> >> by making a quarter-track recording over it, and the tape was played on
> >> a two-track machine, one might think that the two tracks are
> >> overlapping, but using a narrower head (quarter track would be fine for
> >> the later program, a special head is generally needed for recovering the
> >> two-track recording) can recover some of the original recording.
> >> Recording on both sides in quarter-track stereo would likely leave only
> >> very narrow bands (if anything) of the original FT or 2T recording. But,
> >> it's imortant that (c) is not confused with (a).
> >> (d) An oddity worth mentioning here is the oddball track 1-2 / 4-3
> >> two-sided stereo tapes I ran across in the collection of the late Leslie
> >> Huggett. On initial playback they appeared to be two-track mono tapes,
> >> but something didn't feel right about the azimuth setting (by ear), so I
> >> developed them and found them to be 1-2/4-3 stereo recordings (instead
> >> of the almost universally used 1-3/4-2 recording system. In other words,
> >> these were reel tapes using the standards later adopted by cassettes for
> >> stereo. The guard band was definitely visible and of course the two
> >> inner tracks were inside the normal NAB two-track head footprint.
> >> The track configurations and erase head configurations are shown here:
> >> audio/025-reel-tape/
> >> A couple of examples of using the magnetic viewer are here:
> >> agnetic-viewing-system/
> >> (shows a quarter-track tape)
> >> playback-using-the-elevator-head/
> >> (shows a 2-track tape damaged by a malfunctioning quarter-track
> >> recorder's left channel)
> >> Cheers,
> >> Richard
> >> On 2013-02-25 11:51 AM, John Spencer wrote:
> >>> Just a thought, perhaps you are hearing either "print-through", or the
> >>> re-used tapes were not de-maganitized enough to remove the original
> >>> content.
> >>> While I don't consider wikipedia the de-facto standard for all things
> >>> technical, there is an article here:
> >>> http://en.wikipedia.org/wiki/Print-through
> >>> I'm only guessing, but Richard Hess might have some information on his
> >>> site as well:
> >>> www.richardhess.com
> >>> If what you are hearing is somewhat similar to what you are hearing on
> >>> the tape, it's probably print-through. If it is completely different
> >>> material, my guess as I said earlier that the tapes weren't properly
> >>> erased before they were re-used.
> >>> I'm not the resident expert on this by any means, hopefully others can
> >>> help you with some tricks once you have them in the digital domain, but
> >>> I've seen both circumstances. There is no easy fix unfortunately...
> >>> John
> >>> John Spencer ⎮ BMSChace
> >>> [log in to unmask]
> >>> www.bmschace.com
> >>> 615.385.1251 phone
> >>> 615.385.0153 fax
> >>> 615.714.1199 mobile
> >>> On Feb 25, 2013, at 9:52 AM, Henry Borchers wrote:
> >>>> Hi,
> >>>> As I've explained in this list before, I'm currently working with
> >>>> digitizing a number of amateur 1/4" reels from a student radio
> >>>> Since much of the content produced is amateurly engineered, all too
> >>>> often the stock was reused tape. Along with this practice, one finds
> >>>> artifact fragments from previous generation recordings that run for
> >>>> anywhere between a couple seconds to a few minutes. I am wondering if
> >>>> there is a proper name for these fragments. Internally, I have been
> >>>> using the word "ghosts" to describe these fragments but I was
> >>>> if there was a more established name.
> >>>> --
> >>>> Henry Borchers
> >>>> Broadcast Media Digitization Librarian
> >>>> University of Maryland
> >>>> B0221D McKeldin Library
> >>>> College Park, MD 20742
> >>>> (301) 405-0725
> >> --
> >> Richard L. Hess email: [log in to unmask]
> >> Aurora, Ontario, Canada 647 479 2800
> >> http://www.richardhess.com/tape/contact.htm
> >> Quality tape transfers -- even from hard-to-play tapes.