Early Audio Recorders

The Marconi-Stille - page 2

In the photos and descriptions of the various parts of the machine which follow, the three driving systems were:-

No.1 System - Winding. This included the large tape reservoir and its associated thyratron circuit. Also the No.1 motor and the system of belts and pulleys on the lower tier for driving the spool which was taking up the tape (the right spool when the machine was running forwards and the left spool when it was rewinding).

No.2 System - Unwinding. This included the driving wheel to the left of the machine and the small tape reservoir and its associated thyratron circuits. Also the No.2 motor and the associated system of belts and pulleys on the top tier.

No.3 System - Main Tape Drive. Consisted of the constant speed motor, its flexible coupling and flywheel together with the right-hand tape drive system, including the automatic clutch for cutting this out when rewinding.

In addition to the heads and winding systems the machine also included the starter system which consisted of a central starting handle (with an off, two forward and two reverse positions), and mechanical devices for operating the starter switches, for applying braking to the feeding spool and for operating the clutch of the main tape drive system.
The left side of the machine:

Left side
1. Tape jockey arm bearing.
2. Spring jockey pulley.
3. Lower guide wheel.
4. Tape tension brake.
5. Reservoir No.1 entry door.
6. No.2 tape drive wheel.
7. Tape drive belt.
8. Tape Reservoir No.2.
9. Tape tension brake adjustment.
10. Quick release toggle.
11. Tape travel indicator.
12. Pilot light.
13. Red, green and white signalling lights.

Three of the heads:

Three heads

6. 'Stagger' adjusting screw.
7. Lock nut.
8. Clamp.
9. Tape groove.
10. Tape guide.
1. Slot for pole piece.
2. Felt pad.
3. Pressure pin.
4. Spring tension adjuster.
5. Terminals.

The right side:
Right side

1. Tape guide.
2. Tape drive belt.
3. Tape drive wheel.
4. Tape drive wheel clutch.
5. No.1 tape reservoir entry door.
6. Lower guide wheel.
7. Tape tension brake.
8. Tape jockey arm bearing.
9. Spring jockey pulley.
10. Quick release toggle.
11. Tape tension brake adjustment.
The rear with the covers removed, showing the upper tier:
Upper tier

11. Tape travel indicator.
12. Quick release toggle adjustment.
13. Thyratrons (No.1 system).
14. Thyratrons (No.2 system).
15. Relay No.2 system.
16. Relay No.2 system.
17. No.1 motor resistances.
18. No.2 motor resistances.
19. Cue lights.
20. Head connection blocks.
1. No.3 motor.
2. Flexible coupling.
3. Oil-damped flywheel.
4. Tape drive wheel clutch operating mechanism.
5. No.2 motor.
6. No.2 tape drive forward driving pulley.
7. No.2 tape drive forward driven pulley.
8. No.2 tape drive backward driving pulley.
9. No.2 tape drive backward driven pulley.
10. No.2 automatic dog clutch.
The rear with the covers removed, showing the lower tier:
Lower tier

9. Cam-operated mechanism for tape drive wheel clutch.
10. Cam-operated mechanism for brakes.
11. Forward-Reverse switchgear.
12. Operating mechanism for Forward-Reverse switchgear.
13. No.1 automatic dog clutch.
14. Main three-phase connection block.
15. Power transformer (thyratron circuits).
1. No.1 motor (winding).
2. Right hand reel driving pulley (forward).
3. Right hand reel driven pulley (forward).
4. Right hand reel brake.
5. Left hand reel driving pulley (rewind).
6. Left hand reel driven pulley (rewind).
7. Left hand reel brake.
8. Brake springs.