Hammond Organ L-100 Series, Руководство по обслуживанию

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Figure 1–2: L–100 Console, Rear View
Mixed tones from the upper manual and lower manual and pedals
go through the pre-amplifier and the “vibrato amplifier”. Vibrato
may be added, depending on the position of the vibrato selector
tabs. The tones then pass through the expression control and
additional stages of amplifica tion before reaching the speaker.
Percussion tones are produced by borrow ing a signal from the
upper manual 2nd harmonic drawbar, 3rd harmonic drawbar, or
both, and conducting the signal through the percussion amplifier,
where its decay characteristics are controlled.
A portion of this signal is returned to the respective drawbar.
The percussion signal is then combined with the signal from the
manuals after the vibrato system but before the expression control.
The control tubes are keyed through the 6th harmonic key contacts
and busbar.
The pedal tones do not require drawbars for tone color variation,
because they are produced as complex tones by special tone
wheels. The single pedal drawbar adjusts the volume of the
pedals relative to that of the manuals, and the pedal signal then is
combined with the signal from the manuals before passing into the
matching transformer.
1–3 MOTOR AND POWER SWITCH
The tone generator assembly, in which all tones of the
organ originate, is driven at constant speed by a self starting
synchronous motor, operating at 1800 RPM located at the left side
(rear view) of the console (
Figure 1–2 ). (In 50 cycle organs, the
generator speed is 1500 RPM ).
A toggle switch (
Figure 1–1 ) controls power to the organ.
1–4 TONE GENERATOR
DRIVING GEAR
BAKELITE GEAR
TONE WHEELS
COIL MAGNET
BAKELITE GEAR
COIL MAGNET
Figure 1–3: Section of Main Generator
All tones of the organ originate as electrical signals in the tone
generator assembly. It contains 87 tone wheels having various
numbers of teeth, with suitable gears for driving them at various
speeds from a main shaft extending along the center. Each pair of
tone wheels is mounted on a shaft and between them is a bakelite
gear held by a coil spring, forming a mechanical vibration filter (see
Figure 1–3 ). As the gear is not rigidly attached to the shaft, any
pair of wheels which may be stopped accidentally will not interfere
with the operation of the others.