The common;y used DuKane slide film system used a frequency of about 30-50 hz. There were some other systems used later for multi-projector setups that used different frequencies for different cues. I think we still have one of the generators kicking around somewhere... Scott Smith Scott D. Smith CAS On 8/3/2012 8:22 AM, Randy A. Riddle wrote: > When I was in college at App State in North Carolina, Kodak brought a > show to campus that I still remember today. > > It consisted of hundreds of 35mm slides and 8mm or 16mm movie footage > shot by two guys that went on an adventure trip somewhere in the > western US. > > The whole thing was automated with a recorded sound track and racks of > projectors. > > It's a shame that shows like this aren't archived in ways they can be > periodically brought out and redone. > > On Fri, Aug 3, 2012 at 9:14 AM, Shai Drori <[log in to unmask]> wrote: >> From what I have in the archive (mostly cassette) and from memories of my >> youth, the audible tones were for manual advancement and the low frequency >> (about 50-100Hz) were for automatic triggers. >> Shai >> בתאריך 02/08/12 4:03 PM, ציטוט Steven Smolian: >>> I seem to recall that the auto-slide feature, at least for the general >>> public, arrived c. 1960. I remember the big too-doo about the Kodak >>> multi-slide exhibit at Grand Cenral just before the 1963-4 World's Fair. >>> When I worked there, I recall assembling shows for clients and adding the >>> triggering beep which had to be at a certain frequencey. It went onto the >>> "B" channel of a 2 track stereo tape. >>> >>> I think many transcription houses had switched to 12" discs, especially >>> for >>> the classroom market, as that's what I remember being the size player for >>> the film- record player machines of that era. >>> >>> If anyone really cares, a look through the audio and educational audio >>> supply books of the period will have an answer. >>> >>> Steve Smolian >>> >>> >>> -----Original Message----- >>> From: Association for Recorded Sound Discussion List >>> [mailto:[log in to unmask]] On Behalf Of Art Shifrin >>> Sent: Thursday, August 02, 2012 7:52 AM >>> To: [log in to unmask] >>> Subject: [ARSCLIST] voca-film technology >>> >>> Does anyone on this list know if the disks' tones were simply cues for the >>> operator to advance the slides, and or, if a frequency-tuned circuit >>> triggered the next slide? >>> >>> Shiffy >>> >> -- >> בברכה, >> שי דרורי >> מומחה לשימור והמרה של אודיו וידאו וסרטים 8-35 ממ.