Revox C270 Time Code Bedienungsanleitung Seite 15

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8. Alignment instructions
Microprocessor and analog boards 1.777.101.01/02
Only the following boards are to be found in the machine:
(if not, please exchange to the mentioned types)
TC microprocessor board 1.777.101.01 :
TC analog board 1.777.101.02:
Test sets
oscilloscope, probe
adapting cable XLR to oscilloscope probe
voltmeter, sinewave generator
time code generator/reader (AVTC12 was used here)
XLR cables
320 nWb/m alignment test tape with 1kHz recording full track (15/7.5 IPS)
TC alignment test tape order no. 46015
Make interconnections as shown in the picture "Setup TC microprocessor/analog board
Note:
alignment".
Use the flip-out pages showing the test diagrams "TC microprocessor/analog board
alignment" also showing the 0270 TC front and top view.
Test microprocessor
Whenturningthe C270TC on the two LED'sGOODCODE[2] and SAFE'READY[3] will lightup
1.
for approx. 0.5 seconds.
Switch TC generator on and press the button SAVE/READY [4]. The red LED [3] should flash and
2.
the green LED [2] will light up constantly.
Take a previouslyerasedtape and recordit withthe time code. Checkthat the LED SAFE/
3.
READY[3] will be lit up constantlyafter the TC recording has been activatedwith help of the
push button REC and PLAY,as well as SAFE]READY[4]. After deactivatingRECORDthe LED
SAFE/READY [4] will flash again.
Verify withthe volmeterthat a signalon the TC output [7] can be detected.
4.
Test and alignment for analog board 1.777.101.02.
After turningon the C270TC the 2 LED'sGOODCODE[2] and SAFE/READY[3] will light up for
1.
approx. 0.5 seconds.
Reproduce the TC test tape (order no. 46015).
2.
Adjustment of the comparator level with VR7
3.
set the unit to SAVE with help of button [4], the SAFE/READY LED [3] should not light up. Turn
VR7 until GOOD CODE LED [2] lights up. After having verified, by turning the VR7 in its full
adjustmentrange,the area wherethe LED lightsup, set VR7 into the area's mid position(see
diagram).After pressingthe button SAFE/READY[4],the LED GOODCODEshouldbe constant-
ly activated (the LED SAFE/READY [3] must flash).
MPLL alignment with VR4 and TP9
4.
Connect the oscilloscope onto TP9 and adjust with VR4 the signal to a minimum of jitter.
SPLL adjustment with VRI and TP5
5.
Connect the oscilloscope to TP5 and adjust with VRI for minimum jitter, using the TC test tape.
Oscillator level adjustment
6.
Use a standard 1/4" tape. Press the button SAFE]READY [4], the SAFE/ READY LED [3] will
flash and start recording. Verify that no TC signal gets inserted to the C270 TC. Measure the
signal with the oscilloscope on T P3 and adjust with VR6 a sinus voltage of 1OVpp.The measured
frequency is 100 kHz +/- 15 kHz (1 period = 10 PS).
C270 TC
for C270 TC
issue D 1988 with software 1.06 (IC Ul), CIO = IOOnF
issue E 1990 accessable trim-potentiometer VR7 through
a hole drilled into the contacting side
board 1.777.101.01
with VR6 and TP3
RAIOX