Mechanical Installation - Eico HF 12 Instruction Manual

mechanical installation _
a) HEAT DISSIPATION (VENTILATION): In common with
other electronic equipment, the HF-12 produces consider-
ableheatin normal operation. Unless continuous and ade-
quate air flow is obtained around the heat producing ele-
ments, these elements will over-heat and their useful life
will be greatly curtailed.
It Is useful to understand the process of convection where-
by heat is removed In judging the suitabilltyofa location.
Air heated by the heat-producing elements expands and
rises; cool air is drawn from beneath to take the place of
the heated air. In this manner, a stream of air Is set in
motion which continually removes heat from the ampli-
fier. (In particular, we are mainly concerned with the
mcler heat-producing elements; the two EL84 output tubes
and the EZ81 rectifier tube.) If there Is any impediment
to or constriction of the air flow, the essential process of
heat removal wi II be adversely affected.
Adequate venti lotion will be provided if the amplifier is
installed in an open-bock console provided that the top
of the amplifier is spaced at least two Inches below any
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 bock as possible. As an alter-
nate, 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 en-
ter at the bottom and hot air to leave at the top .
If the amplifier Is not installed in a console, it may be
situated on an open surface or on a shelf of a bookcase.
Four rubber feet arealso provided so that the ampliflerwil I
not mar the surface of furniture on which It is placed.
b) EASY ACCESS TO CONTROLS: Mount the amplifier
ata height which will permit easy manipulation of the con-
trols. Tuner controls should be located nearby .
c) ACCESSABllITY TO PARTS: Tubes are the most fre-
quently replaced Items In electronic equipment. If the
amplifier is Installed ina console, sufficient spoce should
bealloted to reach and remove any tube in the amplifier.
Furthermore, input and output terminals of the amplifier
should be accessible to permit easy interchanging of sys-
tem components for comparison, and connection or dis-
connection of a portabl e tape recorder which is stored a-
way when not In use. If antennas are strung around the
back of the console In which the amplifier is installed,
arrange them so they will not interfere with access to the
amplifier.
d) ACOUSTICAL ISOLATION: If amplifier and speaker
are Installed In the same cabinet (not recommended), pro-
vide sufficlent seporatlon to minimize mechanical speaker
vibration reaching the ampllfi er. The minimum seporatlon
Is about one foot.
3
CONSOLE MOUNTING
a) Operations on console front panel preliminary to am-
plifier mounting: (1) Tape the panel template provided
to the face of the console so that the top of the mounting
surface line on the template is level with the top of the
amplifier mounting shelf. (2) Use an awl or a nail to
pierce the centers of the four 5/8" diameter holes for the
controls, the 3/8" hole for the vi ewing of the pilot lamp,
and the two sma II ho Ies for mounti ng the contro I pia te, to
transfer their locations to the console panel beneath. (3)
Remove the panel template. (4) Dri II the holes for the
ponel controls and the pilot vi ewing ho Ie (the two sma II
holes which have been marked are for wood screws).
b) Amplifier mounting in console: (1) Pull off the con-
trol knobs . (2) Remove the control plate, which is at-
tached to the bezel by two screws. (These may be dis-
carded since they are unsuitable for attaching the control
plate to the console panel and two
'4X3/8
wood screws
have been supplied for this purpose.) (3) Fasten the con-
trol plate to the console panel with the 2 '4 X 3/8 wood
screws . (4) If the rubber feet have been inserted in the
bottom plate, remove them. (They may be pried out with
a thin screwdriver. ) (5) Remove the four screws that fasten
the bezel to the side pieces and remove the bezel, which
is not used in console mounting. (6) Place the unit on the
mounting shelf and slide it as for forward as possible, so
that the controls penetrate the panel holes as for as pos-
sible. (7) Place a knob on each control, pressing each
knob toward the chassis firmly so that each control shaft
enters fully into its knob . (8) Draw the chassis bock evenly
and carefully unti I the back rims of all the knobs are equally
spaced from the control plate about 1/8". (9) Wi th a
sharp pencil, draw the outl ine of the side and rear bottom
edges on the chassis shelf. As the bottom plate falls short
of the full width by 3/16" on each side, draw new side
edge lines 3/16" inside the original side edge lines. (10)
Now remove the knobs and take the chassis off the shelf.
(11) Remove the6 screws which fasten the bottom plate to
the chassis. (12) Place the bottom plate exactly in the
outline drawn on the shelf and mark the position of the
center hole on the left side and the center hole on the
right side. (13) Remove the bottom plate and drill each
of the marked holes on the shelf to a diameter of 1/4".
(14) Refasten the bottom plate to the chassis, with the
four of the six
18
X 3/8 screws previously removed, using
the two holes at the rear and the two holes at the front of
the chassis. (15) Replace the chassis on the shelf, position-
ing it exactly in the outl ine previously drawn, and restore
the knobs. This time make sure that the indicator do t on
each knob agrees with the control position. (16) From the
bottom side of the shelf, insert a 18 XI" screw, with 01/2"
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 and when tightened
secure the chassis to the shelf .