Adjustments; Torque In Reverse Picture Search Mode - Grundig VIVANCE GV 3200 VPS Serviceanleitung

Drive Mechanism

4. Adjustments

4.1 Reverse rollers of the threading roller units
– Play a cassette E120.
– Re-adjust the reverse rollers O / P (Fig. 21) if necessary so that the
tape does not curl when running over them.
O
G530
K240
Neigung / Tilt
Azimut / Azimuth
Fig. 21
4.2 Tilt of the combi head
– Play a cassette E120.
– Adjust the tilt of the combi head (G480) using the "Tilt" screw
(Fig. 21) so that the tape just touches the lower edge of the tape
guide R (Fig. 21 / 22). The lower edge of the tape must not curl.
Fig. 22
4.3 Height and azimuth angle of the combi head
– Connect the oscilloscope to the TP302 "A-OUT" (Fig. 24).
– Play the test cassette (6kHz standard audio signal).
– Using the height adjustment screw ("Height", Fig. 21), adjust for
maximum output voltage.
– Using the azimuth adjustment screw ("Azimuth", Fig. 21), adjust for
maximum output voltage.
4.4 X-distance
– Connect the 10:1 test probes of the dual-channel oscilloscope as
follows:
• Channel A: head switching pulse "HD SW" – TP602 (Fig. 24)
• Channel B: FM envelopes "ENV" – TP301 (Fig. 24)
• Trigger: channel A
– Play the test cassette.
– Press the key SW716 (Fig. 25) on the "Keyboard Control Unit right"
followed by the »5« button on the remote control.
Q
– Undo the screw (Fig. 21).
– Insert a screw driver into the oblong hole "X-Position" of the drive
mechanism chassis and adjust for maximum amplitude of the FM
envelopes by altering the mechanical mid-position of the combi
head.
Q
– Re-tighten the screw (Fig. 21).
– Check the reverse rollers of the threading roller units (point 4.1).
– Check the height and azimuth angle of the combi head (point 4.3).
– Switch the unit off.
4.5 Tape tension
– Play back the torque cassette meter in "standard play" mode.
– The tape tension of the left reel must be 42g/cm ±11g/cm (4.2mNm
±1.1mNm).
Otherwise check and replace if necessary the back tension arm
(K240, Fig. 11), the spring of the back tension arm (K248), and the
brake band (K250).

4.6 Torque in reverse picture search mode

– Play back the torque cassette meter in "reverse picture search"
mode.
– The torque of the left reel must be 145g/cm ±30g/cm (14.5mNm
±3mNm).
Otherwise check, clean or replace if necessary the pulley (K200,
Fig. 15) and the reel belt (G542, Fig. 2).
4 - 10
P
Höhe / Hight
G480
G001
G555
Q
X-Position
R
B560
G520
K110 K140
R
Tape
4.7 Tape transport
4.7.1 Coarse adjustment
– Check the tape tension (point 4.5).
– Connect the 10:1 test probes of the dual-channel oscilloscope as
follows:
• Channel A: head switching pulse "HD SW" – TP602 (Fig. 24)
• Channel B: FM envelopes "ENV" – TP301 (Fig. 24)
• Trigger: channel A
– Play the test cassette.
– Adjust the reverse rollers O / P (Fig. 21) so that the FM envelopes
keep the amplitude limit value b / a ≥ 0.63 (Fig. 23) at the tape take-
up side and the tape supply side.
a
Fig. 23
4.7.2 Fine adjustment
– Adjust the X-distance (point 4.4).
– Connect the 10:1 test probes of the dual-channel oscilloscope as
follows:
• Channel A: head switching pulse "HD SW" – TP602 (Fig. 24)
• Channel B: FM envelopes "ENV" – TP301 (Fig. 24)
• Trigger: channel A
– Play the test cassette.
– Manually adjust the tracking so that the picture just becomes noisy.
– Adjust the reverse rollers O / P (Fig. 21) so that the amplitude of the
FM envelopes is as flat as possible.
– The tape rides over the upper edge:
turn the left reverse roller O (Fig. 21) clock-
wise.
turn the right reverse roller P (Fig. 21) clock-
wise.
– The tape rides over the lower edge:
turn the left reverse roller O (Fig. 21) counter-
clockwise.
turn the right reverse roller P (Fig. 21) coun-
terclockwise
4.7.3 Check
– Connect the 10:1 test probes of the dual-channel oscilloscope as
follows:
• Channel A: head switching pulse "HD SW" – TP602 (Fig. 24)
• Channel B: FM envelopes "ENV" – TP301 (Fig. 24)
• Trigger: channel A
– Play the test cassette.
– Press the "Reverse picture search" button then after 15 seconds the
"Play" button. After further 3 seconds the amplitude of the FM
envelopes must have reached its maximum and must be flat. If
necessary re-adjust the reverse rollers O / P (Fig. 21).
– Check the tilt of the combi head (point 4.2).
– Check the height and azimuth angle of the combi head (point 4.3).
– Check the X-distance (point 4.4).
– Check the tape drum position indicator adjustment.
(Adjustment No. 1, page 2-2).
TP303
V-OUT
Fig. 24 TP302
A-OUT
TP301
ENV
TP602
HD SW
TP601
CTL
W350
GND
Fig. 25
SW716
GV 62...
GV 32..., GV 52..., GV 62...
b b a
b/a ≥ 0.63
SW716
GV 32... / GV 52... / SE 14...
GRUNDIG Service