Fostex B-16 - Page 36

11} Depress the ZERO RTN button. (NOTE: Do not directly depress ZERO RTN during
F.F mode. Depress STOP and then ZERO RTN only after tape has completely
stopped. )
12) Adjust MID R306 so that one cycle length of the square wave is a minimum
2.5 ±0. 1msec.
13) Repeat 10) 'V 12) until 2.5 ±0- 1msec. is obtained.
14) Put transport in RWD mode until counter reads -40 % -59S.
15) Depress ZERO RTN button. Observe same NOTE: as in 6), above.
16) Adjust F.F R301 so that one cycle length of the square wave is a minimum
±0. 1msec. of the adjustment results of above 13).
Looking at R301 from the component side of the PCB, the cycle will become
shorter by CCW rotation and longer by CW potation. Also, rotate the pot
very slowly as cycle change response is slow in regards to resistance
change.
17) Repeat 14) 16) until one cycle length of the square wave is ±0. 1msec.
of the adjustment results of above 13) .
18) Wind a maximum amount of tape on the supply reel. Put transport in the
F.FWD mode and set the oscilloscope TIME/DIV to about 0.1msec.
19) Repeatedly adjust HIGH pot R3O7 so that the square wave cycle becomes
0.75 7, 0.80msec. at maximum F.FWD speed (when square wave cycle is
minimum) .
20) Put an empty reel on the supply side, thread tape on transport, put in
RWD mode and when maximum tape speed is reached, confirm the square wave
cycle to be ±0. 05msec. of the results of 19) and in addition, that it is
--------- ----------- : --------- -TRIGGER
I
I
PULSE -
!
— 1 --------------------- + trigger
Fig- 5.11
33