[BC] Secondary & Tertiary Tone

[Harold Hallikainen]

>
> Harold;
>
> The older 'logging' system as used in the Gates SC-48 automation used 8 k
> tone
>
> Of course, this was a VERY CRUDE set-up consisting of a 5-digit number,
> encoded as bursts
> of 8k corresponding to each digit, and drove a decoder consisting of a
> telephone type
> stepper driving a modified Victor adding machine with solenoids in place
> of number keys
>
> All was well until the steppers (5 in the encoder and one in the decoder)
> got some wear on
> them............
>
> Somewhere. I have a slide picture, if I can find it I'll send it to you
> for inclusion on
> your 'page of horrors'
>
> Gary

Thanks for the comment! By the time I got involved, NAB had a standard
that set logging at 3.5kHz.

By the way, my first logging system used Teletype model 15 printers. I had
not yet discovered the UART, so I used a long shift register to send clock
data to the printer. Later, I moved to ASCII (much easier to change BCD
data out of the clock chip to ASCII!) and Teletype model 43 printers.

Speaking of carts, anyone remember the Garron (Ron's Garage) Rapid Cue
machines? I think these were actually a pretty sophisticated design for
the 1970s. After EOM, they'd run fast until they heard anything on the cue
track. Ideally, what they heard was the sped up 1kHz, so they'd stop. So,
the stop cue detector was, instead of 1kHz band pass, a 1kHz high pass
filter. This caused a problem for my logging system, which ran 3.5kHz FSK
between the primary (1kHz) and secondary (250Hz) cues. As soon as logging
would start, the cart would stop. So, I had to add low pass filters so
they would not hear the logging data.

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