Garrard Model 301 Transcription Motor Manual

Introduction

As the owner of this Garrard Model 301 Transcription Motor, you possess a unit whose performance is supreme in its class. This manual has been prepared to enable you to enjoy and maintain the high performance this motor can achieve. Should you require any further information or advice not covered in this manual, please do not hesitate to ask your nearest Garrard agent or write to the Technical Service Department, Newcastle Street, Swindon, who will be pleased to assist you.

Editions: First Edition 1954, Second Edition 1956, Third Edition 1957, Fourth Edition 1958, Fifth Edition 1959, Sixth Edition 1961.

Index

• Description - Page 7
• Operating Instructions - Page 8
• Technical Details - Page 11
• Maintenance - Page 12
• Installation Instructions - Page 13
• Service Adjustments - Page 17
• Spares List - Page 19

This Manual is supplied with Motor number 5.5288.

Description

The Garrard Model 301 Transcription Motor is the culmination of over 40 years of experience in the design and manufacture of high-quality gramophone equipment. This motor is designed to provide the professional user and quality enthusiast with a unit supreme in its class.

The Model 301 features three controls: the speed range knob on the right-hand side, the speed adjusting control in the centre, and the on-off knob on the left-hand side.

It offers extremely low wow and flutter content, with rumble being almost non-existent. Each of the three speeds is adjustable by means of a knob that operates a specially designed eddy current brake, enabling precise speed attainment.

Great attention has been paid to details appreciated by the connoisseur, including a suppressor unit to prevent switch clicks, a heavy turntable diecast in aluminium and accurately balanced, a robust hardened and super-finished turntable spindle, a fully retracting intermediate wheel, and a brake to reduce free revolutions of the turntable upon switching off.

The unit is supplied complete with a stroboscope, a record adaptor for 7" large hole records and clip, a bottle of special oil, all fixing screws, a set of spring suspensions, a template, a manual, and a test report.

Operation

To operate the Garrard Model 301 Transcription Motor, proceed as follows:

1. Move the speed range knob to the desired speed. (See Diagram 1)
2. Place the record on the turntable. (See Diagram 2)
3. Switch on. (See Diagram 3)

To set the speed, place a record on the turntable and then place the stroboscope on the record. Start the motor. Place the pickup on the record and turn the speed adjusting knob until the ring of lines corresponding to the desired speed appears stationary when illuminated under an appropriate A.C. light source. (See Diagram 4)

For highly accurate transcription work where the slightest speed deviation is critical, it is advisable to let the motor run for approximately 10 minutes to reach its normal working temperature. For such critical work, speed should be re-checked after changing the speed range.

To protect the intermediate wheel from damage, the speed change knob is interlocked with the on-off knob. To change the speed range, the motor must be switched off using the on-off knob.

The turntable must not be held stationary while the motor is switched on. The on-off switch on the motor should always be used for stopping.

Technical Details

• Turntable: Diecast Aluminium, 12" diameter, machined all over and accurately balanced. Weight 6 lbs. Fitted with rubber mat. A three-speed stroboscopically engraved turntable is available at extra cost.
• Unit Plate: Diecast Aluminium.
• Motor: Shaded pole induction in heavy cast casing, suspended on six tensioned springs. Magnetically screened.
• Voltage: Dual Range 100 to 130 and 200 to 250 volts.
• Frequency: 50 or 60 cycles according to motor pulley fitted. Alternative pulley available.
• Consumption: 16 watts maximum.
• Wow: Less than 0.2%. (Measured using Gaumont-Kalee Wow and Flutter Meter Type 564, 3,000 cycle constant frequency records at 33⅓, 45 and 78 r.p.m.)
• Flutter: Less than 0.05%.
• Rumble: Almost non-existent.
• Speed Range: 32 to 34, 44 to 46 and 76 to 80 r.p.m. approx.
• Finish: High quality broken white enamel with black accessories.
• Size: Motor Unit 14½" back to front, 13¼" wide, 2¼" above and 3⅛" below undersurface of unit plate. Recommended size for motor board 18" x 18".
• Weight: Nett. 16 lbs. Gross 20 lbs.

Maintenance

The Turntable Spindle, motor, and intermediate wheel bearings are of the oil-retaining type and rarely require lubricating. When lubrication is needed, remove the turntable and sparingly lubricate these bearings with a few drops of the supplied oil. Remove any surplus oil and ensure no oil is present on the motor pulley or intermediate wheel before replacing the turntable.

These oiling points are indicated on Diagram 5. The oil recess in the top motor bearing is accessible through one of the three holes in the aluminium disc of the eddy current brake.

The motor must be switched off before removing or replacing the turntable. The turntable is an accurate taper fit on its spindle. If difficulty is experienced in removing it, tap the spindle top downwards with a small block of wood (such as the handle of a screwdriver) while lifting the turntable. (See Diagram 6 for Spring Suspension details).

Installation

The Garrard Model 301 Transcription Motor should be assembled to a substantial wooden motor board, cut out and drilled according to the template supplied with each unit or to the dimensions given on Diagram 11. Assemble the motor to the board using the rubber washers supplied, placed between the unit plate and the board, to prevent distortion of the plate due to any inaccuracies in the board.

Insert the screws and assemble the washers and nuts as indicated in Diagram 5, tightening the nuts equally a little at a time, then securely tightening the lock nuts.

To protect the electric motor during transit, it is firmly clamped by two transit screws (Diagram 5). These screws, with red heads, must be unscrewed as far as possible to release the motor clamp plate, allowing the motor to float freely on its suspension springs. To clamp the motor for transit, tighten these screws.

The pickup should be mounted on the board according to the manufacturer's instructions.

The motor should be fixed to the motor board as described. However, this may not always be possible due to extraneous vibration caused by closing the cabinet lid or drawer, or by walking across the floor on which the cabinet stands.

In such cases, the motor board should be spring-mounted within the cabinet using the spring mounting assembly shown in Diagram 7. The cabinet board is illustrated in Diagram 8. With the motor and turntable in position, there should be a gap of approximately ½" to ¾" between the two boards. A reduced dimension template for this board is provided in Diagram 12.

On final installation, level the motor by adjusting the inner nuts of the spring suspensions, removing the lower nut, triangular washer, and lock nut for adjustment, and replacing them when the unit is level. The level should be checked using a spirit level placed on the turntable.

A set of four spring mounting assemblies is supplied with each transcription motor and should be assembled as shown on Diagram 6. If the motor board is thicker than ¾", the fixing holes should be recessed 1¼" diameter from underneath to bring the board thickness to ¾" from the top.

Before assembling the motor into the cabinet, connect the power supply lead (if not already fitted) to the power supply terminal block at the rear of the motor. Ensure the lead is securely clamped in the cord grip adjacent to the block. Verify the voltage range is correctly set for the power supply; the links should be set as shown on the terminal block cover and Diagrams 9 and 10. The motor pulley should also be checked to ensure the correct one for the power supply frequency is fitted: a nickel-finished one for 50 cycles, a brass one for 60 cycles.

Should the motor pulley require changing, remove it by loosening the two grub screws holding it to the shaft. When fitting the other pulley, check its correct position before tightening the screws. Move the intermediate wheel inward to ensure the rubber tyre runs in the centre of the appropriate step, and its side face is clear of the pulley step face by ⅛" when set on 33⅓ or 45 r.p.m.

The motor should be earthed by connecting a lead from the earthing tag on the motor (Diagram 5) to a good earth connection. A three-core power supply lead is preferred, with two connections to the power supply terminals and one to the motor earthing tag.

On final installation, ensure the leads from the motor are not strained tight but are loosely looped so the motor remains freely suspended on its springs.

The shaft of the speed range knob is extended to allow for the fitting of a standard wafer switch if required.

Service Adjustments

The Garrard Model 301 Transcription Motor is designed for reliable service with continuous use. These instructions are provided to enable users to make minor adjustments that may become necessary after extended use, ensuring the motor maintains its high standard of performance.

Intermediate Wheel

The accuracy of the rubber-tyred intermediate wheel is crucial for maintaining the unit's high performance. If wow or flutter is suspected, check the intermediate wheel after ensuring the record itself is not at fault. Flutter or bump in reproduction may be caused by flat spots on the intermediate wheel, potentially resulting from the turntable being held stationary while the motor is switched on. Therefore, the turntable must never be stopped by hand; instead, use the on-off switch on the unit plate. If the intermediate wheel becomes damaged, it should be replaced.

Flutter and wow can also be caused by the side face of the rubber tyre on the intermediate wheel rubbing against the side of a motor pulley step. Ensure there is a ⅛" clearance between the side faces of the intermediate wheel and motor pulley steps. Wow can also be caused by oil or grease on the motor pulley, intermediate wheel tyre, or turntable driving surface. In such cases, thoroughly clean all driving surfaces with a clean rag.

Should hum originate from the motor, check that the motor is freely suspended on its springs and that the motor transit fixing screws (Diagram 5) are unscrewed. Also, ensure the power supply and earth leads are slack and not straining the motor on its springs, as rigid leads can transmit motor vibration to the cabinet, causing reproduction issues.

If the motor fails to start, first confirm the power supply is reaching the terminals in the terminal block. If correct, switch off at the power supply and check that the voltage range change-over links are tight. Remove the switch cover and verify that the switch contact moves both switch blades correctly when switching on. Clean the switch blades and contact, and apply a faint trace of Vaseline to each blade before replacing the cover.

If the motor still fails to start, check the coil circuit resistance. It should be 460 ohms for the 200-250 volt range or 115 ohms for the 100-130 volt range.

If the turntable continues to revolve for several revolutions after switching off via the unit's switch, the turntable brake pad likely needs adjustment. To adjust, remove the turntable (as described on page 12), loosen the turntable brake adjusting screw (Diagram 5), move the brake slightly outward towards the rim, and retighten the screw. Ensure the brake is not set too far out, as this can prevent the switch from breaking contact.

Spare Parts List

The following is a list of spare parts for the Garrard Model 301 Transcription Motor:

Diagram 1 (Exploded View of Turntable Assembly)

Diagram 2 (Continued Spare Parts List)

Diagram 3 (Continued Spare Parts List)

Diagram 4 (Continued Spare Parts List)

Diagrams

The manual includes several diagrams illustrating various aspects of the motor, its assembly, and parts. These include:

• Diagram 1: Shows the speed range knob adjustment.
• Diagram 2: Illustrates placing the record on the turntable.
• Diagram 3: Depicts switching the motor on.
• Diagram 4: Shows the stroboscope in use for speed setting.
• Diagram 5: Provides a detailed view of the motor unit, including controls and connections.
• Diagram 5a: A detailed view of the motor's internal wiring and components.
• Diagram 6: Illustrates the spring suspension system for the motor.
• Diagram 7 & 8: Show spring mounting assemblies for the motor board.
• Diagram 9 & 10: Detail voltage range connections.
• Diagram 11: A reduced diagram of the template for the motor board.
• Diagram 12: A reduced template for a subsidiary motor board.
• Diagrams on pages 28 and 29: Exploded views of the motor assembly and its components.