The legendary BBC Radiophonic Workshop closed down in 1998, after 40 years. 50th-anniversary celebrations in 2008, and a just-published book by academic Louis Niebur, titled Special Sound (Oxford), have helped to secure the Workshop's legacy of sonic experimentation, notably the efforts of such figures as Delia Derbyshire and Daphne Oram, and the creation of the theme song and sci-fi sound design for Doctor Who -- not to mention work on Quatermass serials and the Hitchhiker's Guide to the Galaxy.
While I was finishing up a review of the Niebur book, a friend introduced me to the following. Over at the BBC website, there is a treasure trove of old technical monographs from the Radiophonic's heyday. The documents, packed with technical diagrams and detailed descriptions of BBC procedures, date back to the 1950s.
These include, for Radiophonic fans, a great one from November 1963. The monograph series deals with various aspects of the BBC's operations, but this specific one (number 51) is 21 pages long and is entirely dedicated to the Radiophonic Workshop. It cost five shillings upon release, but is available for free download these days. The above image, from Monograph 51, shows a "keying unit" that was rigged up in the studio:
"For convenience in 'playing' sequences of electronicaly generated sounds, a short section (an octave) of a piano keyboard was adapted to make the necessary contacts to the outputs of the bank of signal generators. However, it was soon found that simple on-off switching was very limited in its application ... and the Workshop engineers devised this modification to the keyboard which gave adjustable rise and decay characteristics."
[ PDF link ]
The BBC engineering monographs are listed in reverse chronological order, from December 1969 (#80) through May 1960 (#30) here.
And there are index PDFs contained at this page that have embedded links to the various monograph PDFs.
The BBC documents cover such subjects as "Drop-out in Video-tape Recording," "Distribution Systems for Receiving Stations in the l.f., m.f., and h.f. Bands," and early color-TV testing. Sadly, there appear to be no signs of any Dalek technology in the monographs.