Head Alignment Without Tandberg Test Tapes, Four Tracks; Playback Hea,D; Re C Ord He Ad; Bias H Ea D - TANDBERG 3400 X Service Manual

G,
A
a\
6.
6 . 1
H E AD AL I GNM ENT W I TH OUT
T A NDBE RG TE ST T AP ES ,
F O UR TR AC K
PLAYBACK HEA,D
Height adjustment
Adjust the height of the playback head by means of
the s c rew s A, Figure 10 .1, pa ge 21 . T he upp er e dg e
of the tape shall run flush with the upper part of
the head lamination for channel L. See Fisure 6.1.
Azimuth adjustment
Set the SOURCE/TAPE buttons to TAPE. Play
back a standard azimuth alignment tape with an
a.c. voltmeter connected to each LINE OUT socket.
Adjust the position of the playback head by the
azimuth adjr.rstment screw B, Figure 10.1 until a
maximum reading is obtained on the voltmeters.
6 .2
R EC O R D H E A D
Follow the instructions given in Paragraph 5.3.
6. 3 BI AS HE A D
Follow the instructions given in Paragraph 5.4.
6. 4 ER A SE H E A D
Height adjustments
Adjust the height of the erase head by means of
the s c rew s K and L, s ee Fi gu re 10 .1.
Appr ox im ately 0.25 m m (0 ,0 1" ) of th e fer ri t e
core for the upper track of the erase head should
be visible above the tape, see Figure 6.2.
Upper edge of tape
co incid e s w it h u pp e r
ed ge o f u p pe r p ole
p iece .
Fi7.6.1. Four track playback head.
6 .5 . A L IGN IN G T HE H UM S HIE L D F OR T H E
PL A YB A CK HE AD .
The hum shield for the nlavback head is oositioned
on the pinch roller arm to inut the shield is right in
front of the head during plal,back. Set the deck to
stereo playback with both SOURCE/TAPE buttons
in the position TAPE without tape in the tape path.
Put a piece of paper between the photoelectric end-
stopsensor and the light. Set the deck to PLAY.
Connect an a.c. voltmeter to each of the LINE
outDuts. Hold the shield and loosen screw E
( t lgure l U. I ) one quarter turn.
Pull the shield as far away from the head as the
mounting hole permits. Ad.just the shield sideways
to obtain a minimum reading on both voltmeters,
or best possible compromisel When adjustment
is completed, tighten the screw and seal with
lacouer.
A p pro x. 0. 2 5 mm o f
u p pe r fe rr ite c o re v is ib le
above tape.
I
;
F-ig. 6.2. Four track erase head.