Loading a tape

Start of cipher text

Start hole

Tape layout guide

Tape guides

Image aperture

5 4 3 2 1

The image is reversed by the projection lens so the sprocket cell is third from the left.

Starting with the start of the cipher text on the paper tape,

the tape is first taken upwards over the drive motor pulley 1.

It then comes down and round the first large tape pulley 2 back

up to go over the first pierced multi-track pulley 3. It sits on

the back of the three tracks and the goes horizontally to the

right to go over the rear track of the next multi-track pulley 4.

Now it comes down vertically to the bottom right multi-track

Pulley 5. It loops round this and then goes up and slightly left

to go over the adjustable multi-track pulley 6. Then down to the

bottom left hand pulley 7. Round that and right up to the top

left hand multi-track pulley 3.

This sequence is now repeated until the length of the cipher

text tape has been absorbed.

Finally the tape leaves the bottom right hand pulley and goes

across to the lower of the two solid pulleys 8. By going round

this it joins up with the start of the tape which has come

down through the tape guide in front of the illuminating lamp.

.

The tension on the tape is set by moving up or down the centre multi-track pulley 6 on its girder and then by using the screw adjuster behind the pulley to get the final tension.

The tension is probably correct if the centre of the long vertical section can be moved by finger about one inch horizontally.

The tape reader is then switched on by putting down the 1940’s light switch on the left hand centre vertical girder of the bedstead.