[ Robbie commented:

>[ Typical paper speed is 1.6 inches per second ("Tempo 80"),
>[ therefore 4 inches gap yields 2.5 seconds gap.  CD albums have 4 to
>[ 5 seconds gap.  Would 4 seconds gap, or 6.4 inches, be adequate?

The Selectra was designed to allow the customer to choose the desired
song by turning a selection controller dial on the front of the machine
to the songs numeric location on the roll.  The roll then fast-forwards
or fast-reverses to that location and is triggered pneumatically to
stop its movement and play the desired tune.

The roll is moving very fast in fast-forward and fast-reverse.
Each song goes by at 6 seconds or about 60 seconds start to finish
for the total roll.  The longer the perforation to trigger the
Selectra mechanism, the better.

Original Selectra rolls had three perforations of 2.875" over 9".
These started just after the coin trip perforation on each song.
Six or more inches of blank space between the coin trip perforation
and the start of the music would be much appreciated by those of us
modifying rolls for Selectra use.

Bob Stewart