wide-hole 45 rpm commercial records. Different types of records also require different styli. Turntable
tone arms are equipped with interchangeable cartridges. Although a 78 rpm record is seldom, if ever,
used, a cartridge with a 78 record needle should be available. Be sure to use the 78 cartridge on 78
records only, since its larger stylus would ruin any long playing record immediately. Different
cartridges are used for mono and stereo records. With a stereo cartridge, stereo as well as mono long
playing records can be played. Stereo records should not be played with a mono cartridge. Most tone
arms now have a stereo cartridge which can handle any record except 78s.
a. Stylus. Located on the end of the tone arm. They must be gently cleaned and kept free of
b. Tone arm. Located on a rotating support and balanced for the styli being used. Care must be
used when playing a record; do not hit the tone arm or the styli will be forced across the record and
scratch the grooves.
c. Speed selector lever. Located in the lower left corner of the turntable. Lever has four
positions: 33 1/3 rpm, 45 rpm, 78 rpm, and neutral (located at the top between 33 1/3 and 45 rpm).
d. ON/OFF Button. Located in the lower right corner. Used to start and stop the turntable.
e. Plater. Located in the center of the turntable and covered with a felt pad. The pad is used to
protect the records.
f. Spindle. There are two spindles that come with turntable platers. Both are located in the
center of the plater. The small spindle is for 33 1/3 and 78 rpm records. The larger spindle is spring
loaded and locks down out of the way until needed for 45 rpm records. To raise the 45 rpm spindle,
push down and turn it clockwise and it will come up into position.
Operation of a Turntable:
a. Conduct preoperative inspection turntable and related equipment in accordance with the
(1) Check output/input connectors and ensure equipment is grounded.
(2) Check stylus/cartridge mounting.
(3) Check stylus pressure.
(4) Check speed control switch.
(5) Check function of on/off switch, kick pedal and cue bar.
(6) Clean equipment and record disc.