Teac MT-20D-IO - Page 75

(8) TP9. 10 (threshold level) PCBA Drive Control
TP10 is a test point for measuring the threshold level. TP9 is the
output terminal of the 2.5 V bias power supply which is used as a
reference during threshold level measurement. The threshold level is
represented by the voltage difference (DC voltage) between TP9 and
TPlO.
TP9 and TPI0 are used to check the threshold level.
The voltage difference (DC voltage) between TP9 and TPI0 is approx.
450 mV during write operation, and approx. 330 mV during read
operation. (However, each value is that obtained when the write mode
and read mode are changed over to each other by turning ON/OFF the
WEN signal without moving the tape.)
(9) TPII (output of read level detecting monostable multivibrator)
PCBA Drive Control
Test point for measuring the output of the read level detecting
monostable multivibrator.
TPll is used to check the read level detection delay time. The
signal is the Q output of the monostable multivibrator.
TPll ~~ ______________ ~
lJ-Delay
Example of reading the short block
Fig. 340 Example of waveform at TPII
(10) TP12 (GND) PCBA Drive Control
This point is connected to 0 V.
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time