Hammond Organ L-100 Series, Руководство по обслуживанию

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Page 11
1–5 MANUALS
Musical frequencies from the tone generator go through the
manual cable to terminal strips on the two manuals and from them
to the key contact springs.
Each of the two manuals has 44 playing keys, or approximately
3½ octaves. The two manuals do not cover exactly the same pitch
range, but they are arranged so that keys of like pitch are in line.
Middle “C” is the first C on the upper manual and the key in line
with it on the lower manual.
Under each key are a number of contact springs (for the
fundamental and harmonics of that key) which contact an equal
number of busbars when the key is pressed. All contact springs
and busbars have precious metal contact surfaces to avoid
corrosion, and the manuals are sealed to exclude dust so far
as possible. In case a contact becomes dirty in spite of these
precautions, a busbar shifter is provided in each manual to slide
the busbars endwise and thus provide a fresh contact surface.
(See paragraph “4–7–11 Key Does Not Play or Harmonic Is
Missing” on page 35.)
Looking under the lower manual on the left hand end (front view)
a black wood end block will be observed. One half inch from the
front of this block is a drilled hole. Within this drilling is a small
metal tongue with a punched hole. Using either long nose pliers or
a hook, this tongue can be moved in and out and it in tum moves
the busbars. The upper manual shifter is in a similar place and
access to it is from the rear of the console.
Figure 1–7: Filter Locations and Frequency Terminations on Generator Cover