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B. Tracking Force Explanation
The ability of a cartridge to track properly at low tracking force is very de-
sirable; the wear on the record and the stylus is then kept to a minimum.
However, a stylus tracking at a tracking force too light to maintain contact
with the groove wall (mistracking) can cause permanent damage to the re-
cording. Therefore, the proper adjustment of the tracking force is very im-
portant in terms of both reducing mistracking distortion and insuring max-
imum stylus and record life.
Any stereo pickup in good condition should be able to track Band 5, Side 2
of th'e TTR-103 or 15 cm/sec at the median recommended force. A high
trackability cartridge should be able to track properly on Band 7 or 8 of the
TTR-103 at the median tracking force recommended by the manufacturer.
VIII. ANTISKATING AND TRACKING FORCE OPTIMIZATION USING
THE TRACKABILITY TEST
The trackability test on the Shure TTR-103 is divided into three sections: high
frequency, mid-frequency, and low frequency. The high frequency, 10.8 kHz,
pulse tracking test is recorded on both sides of the TTR-103, Bands 1 through
4; the left channel is on Side 1; the right channel is on Side 2. The mid-fre-
quency tracking test is on Side 1, Bands 5 through 8. The test is a 1,000
+
1,500 Hz lateral cut tone. The low frequency tracking test is on Side 2, Bands
5 through 8. This test is a 400
+
4,000 Hz lateral cut tone. The low and high
frequency tests have four velocities: 15, 19, 24, and 30 cm/sec. The mid-fre-
quency test has four velocities: 20, 25, 31.5, and 40 cm/sec.
Note: THE TTR-103 IS A 45 RPM RECORD.
A. High Frequency Trackability Test
(BANDS 1,2,3, & 4. SIDE 1 LEFT CHANNEL)
(BANDS 1,2,3, & 4. SIDE 2 RIGHT CHANNEL)
Description and Interpretation of
The Test Signal
The high frequency test signal consists of a group of high frequency component
signals, centered at 10.8 kHz and recurring in bursts at a rate of 270 Hz. If this
signal could be reproduced without any distortion, only these high frequency
component signals would be detected. However, any alteration of this signal
produces a detectable component signal at 270 Hz.
In a phono reproduction system, distortion results from such system non-
linearities as tracing distortion, tip indentation, vertical tracking angle error,
stylus dynamics, record wear, electronic signal processing and mistracking.
The contributions to distortion from each of these non-linearities add and sub-
tract from one another, yielding a total 270 Hz signal which is unique for a given
set of test conditions. Although mistracking is the dominant contributor to dis-
tortion, some confusion may result as it is conceivable that one pickup might
have a larger 270 Hz signal while tracking than another pickup has while mis-
tracking.
However, the mistracking contribution to distortion is not only very large, but
also is typically very unstable, and is, therefore, recognizable.
Record warps also cause instability in the 270 Hz signal, but of a different type.
Warps increase and decrease the instantaneous tracking force about the set
tracking force, which can cause intermittent mistracking. This type of insta-
bility is a breakup which occurs at a rate related to turntable speed, whereas
mistracking results in a random instability. In the presence of a warp, the mis-
tracking point has been reached when the breakups are occurring, on a par-
ticular band, most of the time.
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