At 11:00 PM 10/4/99 -0400, you wrote: >At 07:42 PM 10/4/99 -0700, you wrote: >>and broke easily. TAPE usually was either amplitude or frequency modulated >>carrier of about 100 KHz. I don't know about the wire but would suspect >>they would have to do the same thing. > >What kind of tape are you talking about? You don't mean regular cassette >tapes,do you? AFAIK, those are just the raw audio applied to the recording >head (no carriers). > Yup--Or at least thats the way I remember it from my engineering days at Ampex. Scientific and hi frequency analog recorders general y used a HF carrier, that was typically FM modulated. Frequency response depended heavily on the speed of the tape across the head gap versus the width of the gap. Very narrow gaps could run the tape slower. In the olde days, good audio was typically run at 15-30 ips, and I don't recall seeing any 3 ips tapes until about the time I left the industry. Video got around the problem by spinning the head on a diagonal across the tape. Audio--and I'm trying to remember data from 35 years ago--needed to be written with an AM modulated carrier to get the ferrite particles in the tape to magnetize correctly. Playback appeared to be normal audio frequencies straight off the heads. 100Khz sticks in my mind for the carrier. Ampex put out a really good technical book on magnetic recording--might still be available. Kelly William K. Borsum, P.E. -- OEM Dataloggers and Instrumentation Systems & San Diego, California, USA