Operating instructions

Table 2-1
SW1 on the TRANSPORT CONTROL PCA
SWITCH FUNCTION EFFECT
SW1-1 Hand Cueing Capstan ON: Defeats Stop Stand-by input switching, allowing audio to be
monitored while hand cueing in Stop mode.
OFF: Audio output stays in Input mode while in Stop if SW1-2 is on.
SW1-2 Stop Stand-by ON: Switches to Input monitor in Stop mode.
SW1-3 Fast Wind Stand-by ON: Switches to Input monitor in Fast Wind mode.
SW1-4 Play Start Inhibit OFF: Mutes audio output until transport stabilizes at PLAY speed.
SW2 and SW3, which select the head shield functions, are also
mounted on the TRANSPORT CONTROL PCB Assembly. The
functions of these switches are as follows.
Table 2-2
SW2 and SW3 on the TRANSPORT CONTROL PCA
0 (OFF) 1 (ON)
SW2 Shield does not move in Fast Wind mode. Shield retracts in Fast Wind mode
SW3 Independent button control over shields in Unload mode. Shield retracts in Unload mode.
SW2 and SW3 have been set to 0 and 1 respectively when shipped
from the factory.
E. Remove the BIAS CONTROL PCB Assembly (Card #7) and examine
DIP switches SW3, SW5 and SW6 (Figure 2-2). These switches
select the Reproduce and Record EQ for 15 ips (NAB/IEC) and 30
ips (AES/IEC). The switches should be set in accordance with the
specifications of the tape in use. See Figure 2-2 and Table 2-3.
Table 2-3
Reproduce EQ Selection: BIAS CONTROL PCB Assembly
SW3 SW5 SW6 TAPE SPEED EQ CURVE TIME CONSTANT
— — ON 30 ips AES 17.4 µs + infinity
— — OFF 30 ips IEC 35.0 µs + infinity
OFF OFF — 15 ips NAB 50.0 µs + 3180 µs
ON ON — 15 ips IEC 35.0 µs + infinity
SW4 is the Master Audio Attenuation Switch and affects the
operation of SW1-1 on the TRANSPORT CONTROL PCB Assembly.
RV5
SW3
SW4 SW5 SW6
C47 C44
1 111
0 000
ON
OFF
IC3
IC1
IC 18
IC 17
Figure 2-2
Controls on the BIAS CONTROL PCB Assembly
MTR-90III Operation and Maintenance Manual
October 1990
Section 2 Installation
2 - 3