Specifications
TO MAG. INPUT 2
B-1
~~~~-
~,
-
(8-
I
TO MAG. INPUT 1
STEREO
MAG.
CARTRIDGE
FIG. 3
5)
AUXILIARY
B'l,
AUXILIARY
B2: Same as for AUX-
ILIARY
AI,
AUXILIARY
A2 above.
6) AM: This input is intended for AM tuner or the AM
output of an FM-AM tuner where the FMand AM sections
are
independent.
mentioned sources to the correspondmg amplifier input
jack. Unless the source has a low-impedance output such
as a cathode follower (with which up to
50ft.
of
cable
can be used), use the shortest possible connection and
low -
capacity
shielded
cable
(cable having os low as
25mmfd
capacitance
per foot is
available).
7) FM: This input is intended for an FMor FM-AM tuner
where the FM and AM sections are
~
independent.
8) FM
MULTIPLEX:
This input is intended to receive the
output from an FM Multiplex adaptor.
NOTE: A shielded
cable
with a shielded
"phono-type"
plug should be used to connect from
each
of the
above-
d)
TAPE
OUTPUT
I,
TAPE
OUTPUT
2: When no external
amplifier is used in the system, both these outputs are
available
for feeding out to a stereo recorder. When an
external power amplifier is used in the system,
TAPE
OUT-
PUT 2 is used to feed
out
to the external power amplifier.
If it is desired to do stereo recording under the latter
conditions, construct a
device
such as shown in Fig. 4.
Use low
capacity
shielded
cable
for connections.
After checking the ampl ifier for proper operation, remove
all input cables to the amplifier and make the following
control settings which hold throughout the process of hum
adJustment: INPUT
SELECTOR
at
PHONO,
FUNCTION
SELECTOR
at
STEREO,
FOCUS control
at
0,
LEVEL
con-
trol at 10
r
both
TREBLE
controls
at
-5,
both
BASS
controls
at 0;
the
two speaker systems mustbe in phase and
placed
near
one another for this adJustment.
Next,
procede as
TO INPUT 2
I V
lI"1ru
I ,L
OF
STEREO
RECORDER
"'------
1
'"'--_----:....8
I!l
~
6,
(8
I!l
TO
EXTERNAL
POWER
AMPLIFIER
follows: With your
ear
held close to the speakers, insert
the amplifier power plug into the wall
outlet
and listen
to the hum level. Now pull
out
the plug and re-insert it
with the prongs reversed. Choose the prong position with
the least hum. Now connect the tuner input connector to
the amplifier input jack, and with
the
tuner set between
stations and the tunervolume control
set
at a minimum,do
the
same with the power plug of the tuner; use
either
the
117VAC
receptacle
on the HF-81 or one
receptacle
of a
cube tap inserted in
the
117VAC
receptacle
on the HF-81.
Next,
connect the phono cartridge leads to the MAG.
PHONO
1and 2 Inputs, and, with turntable off and
pick-
up arm
at
the rest position, find the insertion position of
the turntable line cord plug
that
yields lowest hum.
Fin-
ally,
connect the
tape
head leads to the
TAPE
HEAD
1
and 2 inputs, and, with the
tape
deck turned off, find the
insertion position of the tape deck line cord plug
that
re-
sults in lowest hum. When all of this is completed,
ad-
just
the
hum
balance
control on top of the amplifier chassis
for least hum.
TO INPUT 1
~OFSTEREO
U~
RECORDER
-dJ
HF81
TAPE
,",liT
OUT
~-----~
._-
... '.
HUM
ADJUSTMENT
2 -
PHONO
RECEPTACLE
STRIP
FIG. 4
e)
POWER
CONNECTIONS:
The line cord of the HF-81
must be plugged into a house
outlet
providing normally
117 volts, 60 cycles AC power. A convenience
recep-
tacle
on the rear chassis
can
be used, if desired, with a
cube
tape
to provide 117VAC power to
the
associated
equipment. This convenience
receptacle
is not switched
or fused and provides 117VAC
at
all
timeS;-regardless
of
whether
the HF-81 is turned on or off.
8