Seeburg 7800, Руководство по обслуживанию

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Service
Manual •41 Models
7800, 7850, 8800
and
9800
clockwise as its corresponding
record comes to playing posi­
tion. A reading can be taken by
first allowing the Symphonola to
come to a stoo after it has
played No. 20-record, tnen lift­
ing the cabinet lid and looking
at the individual escutcheon
dials under
the
shelt'. To reset
the dials, turn them counter­
clockwise b y hand until they
reach the stop position. On
models
8800
and
9800
it wiJ.l be
necessary to open the front door
and turn on light
by
means of
switch on right side of cab:lnet
before playmeter can be read.
2.
A�PL I Fl E.RS
A.
GENERAL
The amplLt'ier in the 1941
Symphonola is the source of
power for all equipment located
in the cabinet
and
also repro­
duces the sound recorded on a
record. The power is supplied
to various units by means
�.i
a
plug and socket arrangement in
which no plug can be put into
the wrong socket. The distribu­
tion of power from the amplifier
c?.n
best be taken up by describ­
ing the functions of each socket
located on the front of the
amplifier panel.
B,
FUNCTIONS OF SOCKETS AND
SWITCHES
The power to all units in
the Symphonola is controlled by
the main switch (Fig. 11, Item l;
Fig. 14, Item
l;
Fig. 17, Item
l).
vlrten this switch is in the down
position, the SymphonoJ.a is in­
operati. ve. With the switch in
the up position, standby power
is suo olied and the instrument
is ready for operation.
The octal socket (Fig.
10,
Item Fig. 13, Item
3;
Fig, 16,
Item supplies 25 vol ts to the
solenotd drum .from which point
the 25 volts supply is distrib­
uted to the various relays and
coils on tne solenoid drum and
elect!'ical selector. This
socket also has two lugs which
are connected to ��e contacts of
the motor control reJ.ay and they
carry the power to the motor and
amplifier when these contacts
are closed. In addition, this
socket provides the power to
operate the counter unit located
on the solenoid drum.
It will be noted that there
is another octal socket (Fig. 10,
Item Fig.
13,
Item 2; Fig. 16,
01
Item This socket supplies
the power to a type
T-3Z
tnms-
mi tter when one is used. F'rom
the schematic diagrams it will
be seen that tnese two octal
sockets {Fig.
9>
Items M-21 and
M-22; Fig. 12, Items M-21 and
M22; Fig. 15 .. Items �t-18 and
!>'.:-19)
are wired in parallel so that the
solenoid drum and transmitter
plugs can be interchanged without
any narm resulting. The small 4
contact socket (Fig.
10,
Item l;
Fig. 1'3, Item l; Fig. 16, Item 1)
receives the R.F. output from a
type T-'3Z transmitter and carries
the output to the A-C J.ine.
The
9
contact socket (Fig.
10,
Item 4j Fig. 13, Item 4;
Fig. 16� Item 4) is the source of
power for any remote control
equipment that may be added to the
Symphonola. The 2 contact outlet
(Fig.
10,
Item 5; Fig. 13, Item 5; -..
Fig. 16, Item 5) supplies power to
111otor when the motor control relay
contacts are closed.