23 Inspecting Stripping Cleaning And Lubricating

2-4. OVERALL INSPECTION.

2-5. Rotate all controls and operate all switches. Pull out all drawbars. Operation should be smooth. Toggles should snap firmly into position. Depress the playing keys; check for proper tension in each case and for cracks and chips. Check the operation of the locking and trip mechanism by striking each preset and adjust key in turn. Be sure that the cancel key releases the associated preset or adjust key on each manual.

2-6. Check the mounting of the reverberation spring system assembly in the tone cabinet. Determine that the locking lever is in its unlocked position; if it is not, unlock as indicated on instruction card on tone cabinet.

2-7. Insert all connector plugs into their receptacles. Plugs should seat firmly and must make good contact. Inspect all connector plugs for loose prongs or pins. Examine all cords and cables for frayed insulation and defective wiring. Check for kinks, bends, or twists.

2-8. Inspect all parts and wiring for rust, corrosion, loose connections, frayed or burned insulation, loose mounting screws and bolts, and burned resistors and coils. Check and tighten all mechanical fasteners, such as screws and bolts. Make a thorough inspection of all tube sockets for broken contacts. Examine all switches for loose or bent contacts and for broken insulation. Inspect springs for proper tension. Be sure that each end of each spring is properly attached to the associated parts. Inspect for any broken parts, evidence of excessive heating and overloading, as indicated by burned resistors or melted wax. Look and smell for these latter troubles.

2-9. Examine all terminal strips, boards, and panels for defective wiring, broken lugs, loose contacts, and signs of burning. Be sure that all screws on the preset panel are securely tightened in position and that all leads are held firmly in place.

2-10. Push down and raise the swell pedal, and note the action of the crank and hinge assembly. Tighten mounting screws where necessary.

2-11. Check the speaker cones for defects. Check the speaker mounting bolts for tightness.

2-12. Inspect all pedals on the pedal clavier for cracks or breaks and for proper tension. (Each pedal should just come up when a 3-pound weight is placed directly behind the pedal sharp cap.) Be sure that the flat spring pushers at the ends of the levers are firmly mounted and are properly seated in place over the pedal switches. (See figure 3-3.) Determine that the felt pad extending over all the plungers is in place and not worn. Adjustable tension springs are made accessible by removing the cover board from the rear of the pedal clavier. If pedals become loose and rebound when played rapidly, increase the tension by tightening the adjustment screws (See figure 1-3.).

2-13. Check the generator anchoring fittings. They should be unscrewed so that the generator floats freely. Be sure that all suspension springs for the generators are connected in position at both ends and are properly positioned.

2-14. Be sure that the console is located on a rigid level surface, so that the generator mounting mechanism, anchored to the generator frame, is free to move in any direction without coming in contact with the wooden shelf of the console bottom.

2-15. Be sure that the tone cabinet is located with the open back placed 2 inches or more from the wall or other obstruction. Be sure that adequate ventilation has been provided.

2-16. Check all tubes for cracks in glass or base, and for bent or broken prongs. Inspect for firm mounting of the tubes in their sockets. Test tubes for low emission, leakage, and short circuits. Test all tubes at least semi-annually, and replace them at least every 18 months. Inspect pins and bases for accumulations of foreign matter.

2-17. As the Model C-3 Hammond Organ is used in chapels and auditoriums, it is unlikely that inspection will find the organ deteriorated be yond repair, except where it has been subjected to fire or explosion.

2-1 8. REMOVAL AND REPLACEMENT OF PLUCK-OUT PARTS.

2-19. VACUUM TUBES. The following instructions apply when it is necessary to remove and replace vacuum tubes.

a. Table I lists the tube complement of the Model C-3 Hammond Organ and Model PR-40 Tone Cabinet.

e. Compressed air.

f. Crocus cloth.

2-24. Remove corrosion, rust, or dirt. Blow out dirt and dust from the interior of the console and the tone cabinet. If an air hose is used, be sure that any water which may have condensed in it is blown out before applying the air stream to the equipment. When using compressed air to remove dirt, be careful not to disturb the wiring. Scrape off tar or other adhering foreign matter;

TABLE I

Unit

Tube

Quantity

Unit

Tube

Quantity

Console Preamplifier

6AU6

2

Power Amplifier

5U4GB

2

6C4

2

(in PR-40 Tone Cabinet)

6AU6

2

6X4

1

6BQ5

6

12AU7

1

12AU7

1

12AX7

1

12AX7

2

12BH7

1

12BH7

1

b. Never remove tubes from the amplifiers when the organ is turned on. Avoid working on the tubes immediately after shut-down; severe bums may result from contact with the envelopes of hot tubes. Never jar a warm tube.

c. When replacing a defective tube, do not jiggle the tube from side to side in its socket. Movement of the tube weakens the pins in the base and unnecessarily spreads the contacts in the socket. Replace the defective tube; be sure that the replacement is pressed down firmly in its socket.

2-20. PEDAL CLAVIER. The following instructions apply when necessary to remove and replace the pedal clavier.

a. Remove the bench positioned over the pedal clavier.

b. Lift the console end of the pedal clavier and pull slightly up and out.

c. To replace the pedal clavier, place it in position, lifting slightly at the front, and slide it under the console until it locks in place. Place the bench in its proper position over the foot pedals.

2-21. CORDS AND CABLES. Disconnect cords and cables by firmly grasping the connector plug and pulling it.

2-22. CLEANING.

2-23. The following materials are required to perform cleaning operations on the Model C-3 Hammond Organ:

a. Clean cloth.

b. Dry-cleaning solvent.

c. Paint brush with camel's hair bristles.

d. Lint-free, bleached cloth.

touch up with paint or lacquer if necessary.

2-25. Clean the vacuum tube sockets and pin receptacles with solvent and a camel's hair brush. If necessary, clean pins with crocus cloth.

2-26. Clean all wooden parts and playing keys with a clean, lint-free cloth. Accumulations of dirt and dust in the key contacts may be removed by adjusting the bus bar shifters. (See paragraphs 4-9 to 4-13 inclusive.) No disassembly is required.

2-27. LUBRICATION

2-28. APPROVED LUBRICANTS. The following listed lubricating material is required to service the Model C-3 Hammond Organ. Nomenclature Stock No. Class Source Lubricating Oil- 14-02834-10 06-B AF Stock Preservative, Special, Spec MIL-L-644

2-29. CONSOLE. Some moving parts receive lubrication by capillary action via cotton threads connected to the central oil trough. Oil is fed to this trough from two oil cups. (See figure 2-1.) To gain access to these oil cups, remove the rear dust panel by unscrewing the two thumbscrew bolts. Every year fill the oil cups three-quarters full with oil, Spec MIL-L-644. (The oil level will slowly drop; however, do not continue adding oil.)

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  • randall
    How inspect hammond organ?
    1 year ago

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