Central Southern England ILR Digitisation Project – techinical report

Projects managed by the Centre for Broadcasting History, Bournemouth University, have been incredibly lucky to be able to draw on expert knowledge from the Project Team members. As the South Southern England ILR project moves to its final phase, John Moxley our Technical Consultant shares some of the challenges in digitising open reel audio tape.

Introduction

A total of 1343 items were copied, initially to CD, from four ILR Stations in the South of England – Radio Victory (now defunct) in the Portsmouth area; Ocean Sound (Victory’s successor) covering Hampshire and the Isle of Wight; Radio 210 in the Thames Valley; and Two Counties Radio (2CR) in Dorset and West Hampshire. The material dates from 1975 to 1990 and is held at the Wessex Film & Sound Archive in Winchester.

Technical issues

Sticky Tape

In the 1970s and 1980s recording engineers favoured the Ampex brand of audio (reel-to-reel) tape. Ampex has since become well known for its principle flaw – sticky syndrome. Sticky tape causes the player’s transport system to slow resulting in pitch variation and other incongruities. Sticky tapes deposit oxide residue on the tape heads and transport system which then require regular cleaning. In some cases effected tapes can be baked in a laboratory convection oven. This conditions the tape so that it can be played once, giving a single opportunity to recover the audio content. Even with this, a number of Ampex tapes were too sticky to copy successfully. Associated with this problem was that some programme tapes contained various formulas including Ampex, and this often resulted in a poor CD transfer. It was not possible to know about this variation in format until the tape was played, and in some cases retakes were necessary.

Edits

In the analogue open reel era recordings were edited by cutting and joining the parts with glued strips. Over the years some of this glue has dried out causing the tape to break and also damaging the machine heads. In addition to this there were different thicknesses of tape. Broadcast recordings were usually made using the best quality materials, but occasionally very thin tape was used which gave an impaired audibility and was prone to breaking. Not infrequently a tape broke or the machine heads became clogged with bad tape during transport, and the CD had to be aborted.

Tracks and bands

Most programme tapes were divided into bands with coloured leader tape denoting advertisement and other breaks, and their CDs could easily be recorded with corresponding tracks. However many tapes, mainly compilation news reports and unedited rushes, were not banded in this way and for research purposes it was thought useful to transfer each report to a separate CD track. Before doing this, the tape had to be listened to so that tracks could be incremented at the correct places. Sometimes cue sheets were available to help, but often this was not the case. The CD tracking process was further prolonged because the Fostex CD recorder bought for the Project did not permit erasing a track, even on a rewritable disc. If an error was made in writing track 5, that track could not be undone and re-recorded; the entire CD had to be erased and re-formatted.

Pitch and Speed

Some tapes varied in speed and pitch. For example, a Radio 210 news compilation that must have been originally recorded on a faulty machine; the pitch had to be constantly varied and the resulting CD, though not perfect, is the best sound achievable. In another example, Radio Victory compilation of advertisements at different speeds that enhance or impair the quality. Both these examples required CD tracking as described above. A few tapes played at speeds slower than usual broadcast quality, and for these other machines were required. The slow speed had been used so that the programme would fit on to one tape. But it would not fit on to one CD. Another 2 tapes contained recordings of a four-hour Ocean Sound sports fixture, each tape producing two CDs. Among the Radio Victory collection was a number of logging tapes that ran at ultra-low speeds recording an entire day’s programme output. For these a specially modified machine had to be purchased and a number of CDs produced from each tape. The digitisation of these logging tapes was a long process.

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