Hammond Organ L-100 Series, Service Manual

Page: 10 / 87

Page 10
Adjacent to each tone wheel is a magnetized rod with a pickup coil
wound on it. These magnets extend through the front and back of
the generator, and are held by set screws which can be loosened
in case adjustment is ever necessary.
Figure 1–6 shows the
location of the magnet for any frequency number. In the illustration
the dotted lines indicate frequencies whose tone wheels are on the
same shaft.
On top of the tone generator assembly are small transformers
and condensers, forming tuned filters for the higher frequencies.
They are not likely to need replacing. In case one filter becomes
inoperative, both the transformer and condenser must be replaced
with a matched set from the factory.
Figure 1–7 shows the location
of these filters. A few frequencies use untuned filters consisting of
coils alone.
Wiring from the various filter assemblies leads to the terminal strip
on the long edge of the generator.
The output frequencies of the tone generator are numbered, for
convenience, in order of increasing frequency. The lowest, number
1, is about 32 cycles per second, and the highest, number 91,
is about 6000 cycles per second. Frequency numbers 1 to 13
are used only for the pedals; numbers 14 to 17 are omitted; and
numbers 18 to 91 are used for the manuals.
Figure 1–7 showing
filter locations also shows the termination point of each frequency,
while
Figure 1–5 shows typical tuned and untuned tone generators.
In case any generator frequency is weak or absent, refer to
Practical Service Suggestions for the procedure to be used in
locating and correcting the trouble.
Figure 1–6: Magnet Locations on Tone Generator