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.