Scully 280 Series - Page 12

OPERA TI:->G
d. Hewilld - The lell blue pushbutton
ewitch the maclUM in the Rewtnd or
Fast Rc,'crse mooc.
Fast Forward The right blue push-
buttoo switch operate, the machine in the f"ast
Forward mode.
I. - The white illuminated push-
button sV,'itCh discontinues all operating functions
when
dcpressed. This button continues to 00
illuminated as long the AC power switch is
In the ON position anol thus acts as the tape
transport pilot light.
.s:. Start - A green pushbutton switch
which controistape motion in the play mode a l so
providcs power ncce,sary for thc HECOHD
lunction .
g. Capstan Sp<:ed Switch - This switch
selects the or low spee<lol the drive motor
(normally a two - speec motor) amt also selects
the proper record and playback equalization in
the ampl!liers .
i. Edit - A yellow pushbutton sw!tch
which, permits tape to mO"C in
the start mode without winding onto the takeup
reel. The tape brake arm is also inoperative.
1, External drive to capstan motor -
A socket is provided on the under side of the
relay <;hassis to allowexternai drive to the cap_
stan motor. This can toe used,
(1) As a meanS 01 connecting a more ac -
curatc 60 cycle source to tile capstan
motor. This rray be ""sir e d in instru-
mentation type recording, and where the
local [Xl"'cr
frequency is not reliable
(2) To create speCial ef(ects, by off speed
playback Or recordmg,or
(3) For "ynchrnnou$ playback 01 h Im
sound
tracks.
A 150 watt am?lif i er with an output im_
pedance of 150 ohms is suitable for driving the
motor. (For intermittent Operation
,
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a i' e 10
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amplifiers may De The mo tor
circuit ie On 1 a n d 8, pi" 1 is
common with one side o( the AC line.)
!I connections are made to pi ns O ther
than and 8 the wiring should be checked for
compatalJility oofo,"" applyi"g power. Not mOre
than
I amp should be drawn Irom pin 3. and not
more than 2 amps tOl,,] Irom 1.3 and 7,
Pins 5 and 6 provi<!c 24 volts al 100 rn" in the
record mo;ie.
3 .2.2. Electronics Assembly Front Panel
(See figure 3 - 2.)
a. Record I", .. el - Providcs for the
control of the rccord amplilier lcvcl as indi -
cated by the VU meter when the monitor switch
is in the record positlon.
b. Function Switch _ A fh'e-!X'sition
s"'itch That selccts MIC or LINE iO)}lltlor thc
record amplifier, SAI'£ to prevent accidental
erasure, ,YNC lor channel synchronizatioo
cal""billty, and DEMAG which Isolates the mag-
ndic heads from the e l ectronics, allowing the
operater to dcmagnctize thc "'ithout risk
of transistor damage . The SYNC position ts
norrnallyfunctionatonly on lhree and four chan -
nel model!;.
c. Mon it or Switch - A four-posltlon
switch that the pliy Or record eleclronic
functions .nd allows visual monlter!ng of their
respective levels on the VU m€ter . The third
position provides monltor!ng of the rec-
0rd arnptllier and v!sual mon!torlng 01 thc re -
corder bias leve l on the meier. The fourth po -
sitton pro'ides an audible monitoring 01 the play
amp li fier and a visual mooltorlng 01 the erase
lcvcl.
d. Playback uvc I - The Playback Le,'e I
Controllndudes a Calibrate poSition lor sctting
desired reference level. This is marked CAL
on
the d ial of the playback level control. This
CAL position is utlllzed!n conjunction with the
reference set trimmer, Ident!l!e<l as HEI' SET
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l'igure 3-2. Electroni< 's Assembly Front Panel