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mechanical
installation
GENERAL
a)
HEAT
DISSIPATION (VENTILATION): Incommonwith
other electronic
equipment,
the
HF-85
produces consid-
erable heat
In
normal operation.
Unless continuous
and
adequate
air
flow
is
obtained around
the
heat producing
elements, these elements
will
over-heat and
their useful
life
will
be
reduced.
Adequate
ventilation
will
be provided
if
the
HF-d5
is
installed
inan
open-back
console provided
thot
the top of
the
unit
is
spaced
at
least
two
inches
below
<xiy
shelf
mounted above
it.
IF
the
cabinet
Is
enclosed
at
the
rear,
provide
several large holes or
slots
as
low
down
and
as
high
up
in
the cabinet
back
as possible.
As an
alternative,
holes
may
be provided
in
the
sides,
bottom, or top of the
cabinet.
The
important thing
to
remember
is
that effective
ventilation requires provision
for
cool
air
to
enter
at
the
bottom and
hot
air to
leave
ot
the
top.
If
the
HF-85
is
not
installed
in
a console,
it
may
be
sit-
uated on an
open
surface or
on
a
shelf
of
a bookcose.
Four rubber
feet
are
also
provided
so that
It
will
not
mar
the surface
of furniture
on which
It Is
placed.
b)
EASY ACCESS
TO
CONTROLS:
Mount
the
preampli-
fier at
a
height
which
will
permit eosy manipulation of
the
controls.
e)
ACCESSIBILITY
TO
PARTS:
Tubes
ore the
most
fre-
quently reploced
items
in
electronic
equipment.
If
the
preamplifier
Is
installed
in
a
console,
sufficient
spoce
should
be
alloted
to
reach
and remove any
tube
in
the
unit.
Furthermore, input
and
output
terminals of the
pre-
amplifier should
be
accessible
to
permit easy Interchang-
ing of system
components
for
comparison.
If
antennas ore
strung
around
the
back
of the console
in
which
the
pre-
amplifier
is
installed,
arrange
them
so
they
will
not in-
terfere
with access
to
fhe
unit.
d)
ACOUSTICAL
ISOLATION:
If
preamplifier
and
speaker
are
installed
inthe
same
cobinet(not
recommended),
pro-
vide sufficientseparationtomlnlmize
mechanical speaker
vibration
reaching
the preamplifier
which
may
result in
mtcrophonicsand
howling.
The
minimum
separation
Is
o-
bout
one
foot.
A
baffle,
usually the preamplifier
mount-
ing
shelf,
should
be
present
between
preamplifier
and
speaker.
In
extreme
coses,
it
may
be necessary
to
mount
the preamp]
if
ier
on sponge
rubber
pods.
CONSOLE
MOUNTING
a)
Operations on console
front
panel preliminory
to
[ye-
amplifier
mounting
:
(1)
Tape
the
panel template provided
to the
face
of the console
so that
the top
of
the
mounting
Mirfoce
line
on
the
template
is
level
with
the top of the
amplifier
mounting
shelf. (2)
Use an awlornallto
pierce
the centers of the
four
extreme
outers holes
For
mounting
the
control
plate, to transfer their
locations
to
the
con-
sole
panel beneath.
(3)
Trace
out the rectangular cut-
out with an awl
or
nail
ond
then pierce
the centers of the
Four 1/2"
holes,
one
in
each
corner of the
cutout.
(4)
Remove
the
panel template.
(5) Drill
the four 1/2" holes
in
the
console panel,
one
in
each
corner
of
the rectan-
gular cutout
area.
Cut
out the rectangular piece with a
keyhole
saw, using
the four
1/2" holes
as starting holes.
b) Preamplifier
mounting
In
console;
(1) Pull off
the
con-
trol
knobs.
(2)
Remove
the four screws
that fasten the
bezel
to
the
side
pieces
and remove
the bezel.
(3)
Re-
move
the
two
screws
and
nuts that Fasten the control plate
to the bezel.
The
bezel
it
not used
In
console mounting.
(4)
Fasten the control plate
to the
console panel with
the
two ^4
X
3/6
wood
screws
supplied.
(5)
If
the rubber
feet
hove been
inserted
in
the
bottom
plote,
remove
them.
(They
moy
be
pried
out with a
thin
screwdriver.)
(6)
Place
the unit
on
the
mounting
shelf
and
slide
It
forward
until
the slideswitch support l^oekets are
up
against the
panel and both
slide
switches
oceeuible from
the
front;
the
control
shafts
should
be
approximately centered
In
the corresponding holes
in
the control plate.
(7)
With a
sharp
pencil,
draw
the outline of the side
and
rear
bottom
edges on
the
chassis shelf.
As
the
bottom
plote
falls
short
of
the
full
width by 3/16"
on each
side,
draw
new
side
edge
lines
3/16^
Iruide
the original side
edge
lines. (8)
Now
remove
the
knobs
and
take
the
chassis off the
shelf.
{9)
Remove
the
6
screws
which
fasten the
bottom
plate to
the
chassis.
(10)
Place
the
bottom
plate exactly
in
the
outline
drown on
the shelf
and mark
the
position of the
center hole
on
the
left
side
and
the center hole
on
the
right side.
(11)
Remove
the
bottom
plate
and
drill
each
of the
marked
holes
on
the shelf
to
a diameter
of
1/4".
(12)
Refesten the
bottom
plate
to the
chassis,
with the
four of the
six
screws
previously
removed,
using
the
two
holes at the rear
and
the
two
holes
at
the
front
of the
chassis.
(13)
Replace
the chassis
on
the
shelf,
positioning
it
exactly
in
the outline previously
drawn,
and
restore
the knobs.
This
time
make
sure that the In-
dicator dot
on each knob
agrees
with
the control
position.
(14)
From
the
bottom
side of the
shelf, insert
a^Sx!"
screw, with
a
1/2"
flat
washer
against the head, through
both
the
left
and
right side
center
holes.
These screws
engage
the
stamped
nut
over
each
hole
on
the
chassis
flange
ondwhen
tightened secure
the chosslsto theshelf.
3
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