Table of Contents
Advertisement
2.7 TAPE INTERCHANGEABILITY ADJUSTMENT
NOTE : ¢ This adjustment is extremely important. However,
it is normally not required during routine service.
Perform only after replacing major components(A/
C head,upper/lower drum assembly,pole base
assembly, etc).
* Before using costly alignment tape,use a spare
tape and confirm correct operation of the tape
transport.
2.7.1 Tape pattern
(1)
Connect the oscilloscope to TP106(PB FM) on the Main
board.Use TP111(D.FF) on the Main board as a trigger.
(2)
Playback the SP stairstep portion of the alignment tape
([MHPE].Confirm that the FM waveform appears as in-
dicated in Fig.2-7-1.
(3)
Set the manual! tracking position by pressing the ///
button on the remote controller or TV PROG °-" and "+'
buttons simultaneously.
(4)
Operate the tracking adjustment (press the TV PROG
buttons during playback)
and set for maximum play-
back FM waveform.
(5)
By operating
the
TV
PROG
button,vary
the
FM waveform from maximum to minimum and vice
versa to confirm that the waveform varies nearly in a
flat shape as shown in Fig.2-7-1.
(6)
When the FM waveform does not remain flat during
this process,first slightly loosen the set screw located
at the bottom of the guide rollers.Using the guide roller
adjustment tool (Roller driver) ,adjust the supply and
take-up guide rollers (refer to Fig.2-7-2) to obtain the
correct waveform as indicated in Fig.2-7-3.
(7)
By pressing the TV PROG buttons several times, vary
the FM waveform output from maximum to minimum
(and vice versa) gradually,and confirm that the variation
proceeds in flat shape, as shown in Fig.2-7-3.
(8)
Next playback the LP stairstep portion of the alignment
tape [MHPE-L] and adjust the tracking control from
maximum to minimum the FM waveform,confirm that
FM waveform variation is always flat.
(9)
Record the signal and play it back in both of the SP and
LP mode,confirm that the FM waveform is flat in both
mode.
(10) After adjustments, tighten the set screw of the guide
rollers.
(11) Confirm that the tape wrinking does not occur at the
roller upper or lower limits as indicated in Fig.2-7-4.
TTR
TE
Maximum
level
Minimum
level
Normal
waveform
examples
ANT
oa
wy,
i —
(inset
CT iII«,», 7
incorrect waveform
examples
Fig. 2-7-1
Adjust Roller driver
Hex wrench
wen side
t
i
i}
1
i
1
i}
1
= {iin
ake-up side
+ Correct variation of the waveform ( always fiat)
ee
Ee
+ Bad variation of the waveform
Raising
Failing
AT ~ jaamopa
Fig. 2-7-3
Incorrect
Correct
WOWoed
(a) Guide Roller
tide]
(b) Guide Pole
Fig. 2-7-4
2.7.2 A/C head height & azimuth
NOTE.
©
(GIMIPOIally S06 AUC NGA NOTH AF ARCAOT WF
Fig. 2-5-4.
¢ Use spare tape to check the transport and con-
firm the tape is not scratched or damaged.
1. Tilt
(1) Use spare tape and set for playback.
(2) Turn screw (3) clockwise to where the tape curls just
slightly at the TU guide pole bottom flange as shown in
Fig.2-7-5.
(3) Then slowly turn screw (3) counterclockwise to where
the curling ceases.
2. Height
(1) Connect CH-1 of a dual trace oscilloscope to Audio Out.
(2) Connect CH-2 to TP1101( CTL PULSE) of the Main board
assembly and use the ALT mode.
(3) Playback the SP stairstep portion of the alignment tape
IMHPE].
(4) Adjust screws (1),(2} and (3) for maximum audio output
and control pulse level.
3. Azimuth
(1) Connect the oscilloscope to Audio Out.
(2) Playback the SP stairstep portion of the alignment tape
[MHPE].
(3) Adjust screw (2) so that the audio output is both maxi
mum and with minimum fluctuation.
Fig. 2-7-5
2-15
Advertisement
Table of Contents
