Fostex A-8 - 5. Routine Maintenance; Cleaning Procedures

by R16 and C6, Ul-3 goes to "H" (decode mode) .
U6-4 is the IC for controlling the master bias, and its output goes to "H"
level when any one track goes to the 1 encode mode, and to "L" level when all tracks
are put in the decode mode.
4.12 MONITOR SELECT CIRCUIT
If the MONITOR selector is set to INPUT when the record/reproduce amplifier is
in the decode (reproduce) mode, that channel only goes to the ENCODE (record) mode,
and the monitor output is changed from reproduce output to record input.
When MONITOR select 1 is set to INPUT, an "L" Level is applied to U3-8 and
thus U3-10 goes to "L ” which is applied to Ul-2. Under this condition, if the GROUP
select is at GROUP 1^4, then U8-1 will be at "L" and CHAN 1 will go to the ENCODE
mode.
If the GROUP select is at GROUP 5 % 8, U6-9 will be "H" and thus U6-10 also at
"H" to make CHAN 1 go to the DECODE mode but then, U4-10 will go to " L" and thus
CHAN 5 goes to the ENCODE mode.
5. ROUTINE MAINTENANCE
Troubles and breakdown in the recorder can be prevented by scheduled checking
and maintenance. Periodically follow the check items listed below:
a) Cleaning the heads and tape guides
All heads and guides in the tape path must be cleaned after each 6 hours of
operation or before starting a new session of recording.
Cleaning fluids specially prepared for tape recorders is recommended,
b) Cleaning the pinch roller
Clean at least once after each full day of use.
A cleaning fluid which will not attack rubber must be used.
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