Fostex X-24 Service Manual page 9

output in the high region and dropout (some parts of sound not reproduced) are typical symptoms. It is therefore
recommended to clean the heads periodically before recording and playback to avoid such troubles.
2) Capstan and pinch roller
Buildup of magnetic particles and dust on these parts will cause increase in wow, flutter and wrapping of tape on
the capstan. Thus, these parts must always be kept clean. Cleaning is done with cotton buds moistened with fluids
prescribed or recommended for tape recorders and especially the heads. Never use lacquer thinner, acetone or
other organic solvents.
3-1-2. Demagnetizing
The REC/PLAY head becomes magnetized by extended use or when the head is touched with a magnetized object.
As a result, frequency response especially in the high region will deteriorate, noise level increases, and in some
cases may transfer noise to valuable prerecorded tapes. For this reason, do not touch the head with magnetized
screwdriver and scissors or allow DC current to flow through the head winding such as when testing continuity
with a circuit tester. Should the head becomes magnetized, demagnetize it with a head demagnetizer designed for
this purpose.
Demagnetizing Procedures
1) After turning off the power of Model X-24, open the cassette lid and if a cassette tape is loaded, remove and place
it far away from the deck.
Switch on the head demagnetizer while holding it about one meter away from the Model X-24. Then, slowly move
2)
the head demagnetizer tip to the head and wave the tip up and down several times close to the head surface.
3) On completing the above procedures, slowly draw the demagnetizer away from the head and switch it off when it
is more than one meter away from the head. As demagnetizm in the head cannot be seen, unlike the soiled head,
routine demagnetizing is necessary. It is recommended to do so at the same time the head is cleaned.
3-2. Test Equipment and Adjusting Tools
The following tools and equipment are required for adjusting the Model X-24.
1)
Head height and tape contact adjusting jig
2)
Torque meter
Cassette torque meter
Cassette torque meter
3)
Mirror tape cassette
4)
Test tape
Speed / Flutter (3 kHz)
Reference playback level
Playback frequency response
5)
Blank tape
6)
Audio oscillator
7)
Frequency counter
8)
Bandpass filter
9)
AC voltmeter
10)
Oscilloscope
11)
Wow & Flutter meter
12)
Distortion meter
13)
Frequency counter
Model 9001 (P/N: 8286001000)
TW-2231 (P/N: 8286008000): 0 ~ 200 g-cm (0 ~ 2.8 Oz-In)
TW-2111A (P/N: 8286009000): 0 ~ 100 g-cm (0 ~ 1.4 Oz-In)
TCC-902 (P/N: 8286002000)
Model 9152 (P/N: 82660022000)
Also 3150 Hz test tape for Wow & Flutter measurement is
recommended.
TCW-231 (P/N: 8266002000)
TCW-284F (P/N: 8266003000)
C-90 or shorter tape, TYPE II / HIGH position
General type
General type
General type
Stereo type is recommended.
General type
General type
General type
General type
X-24
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