mechanical Installation
a) HEAT DISSIPATION (VENTILATION): In common with
other electronic equipment, the HFT-92 produces consid-
erable heat in normal operation. Unless continuous aid
adequate air flow is obtained around the heat producing
elements, these elements will over-heat and their useful
life will be greatly reduced.
Adequate ventilation will be provided if the tuner is in-
stalled In an open-back console provided that the top of
the tuner is spaced at least two inches below any shelf
mounted above if. 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 aspossible. As an alternative,
hales may be provided in the Jides, bottom, ortop 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 at the top.
If the tuner is not installed In aconsole, it may be situated
on an open surface oron ashelf of abookcase. Four rub-
ber feet are also provided so that the tuner will not mar
the surface of furniture on which it Is placed.
If it is considered essential, because of space limitations
to "stack" a matching amplifier such as the HF-12 with
the tuner (not recommended for reasons described above),
place the wnpllfier above the tuner since the amplifier
produces substantially more heat aid requires more venti-
lation.
b) POSITION: The specified absence of tuning drift can
be fully assuredonly if the tuner is placed in an approxi-
mately horizontal position, which is therefore strongly
recommended.
c) EASY ACCESS TO CONTROLS: Mount the tuner at a
height which will permit easy manipulation of the con-
trols. Amplifier controls should be located nearby.
d) ACCESSABIL1TY TO PARTS: Tubes are the most fre-
quently replaced items in electronic equipment. If the
tuner Is installed in aconsole, sufficientspace should be
al lotted to reach aid remove any tube in the tuner. Fur-
themore, antenna and output terminals of the tuner should
be accessible to permit easy interchanging of system com-
ponents for comparison. If aitennas are strung around
the back of the console in which the tuner is installed,
arraige them so they will not interfere with access to the
tuner.
e) ACOUSTICAL ISOLATION: If tuner andspeaker are
installed in the same cabinet (not recommended), provide
sufficient separation to minimize mechanical speaker vi-
bration reaching the tuner which may result in microphon-
ics and howling. The minimum separation is about one foot.
Abaffle, usually the tuner mounting base, should be pres-
ent between tuner aid speaker, in extreme cases, it may
be necessary to mount the tuner on sponge rubber pods.
CONSOLE MOUNTING
NOTE: The tuner may be installed in aconsole with the
slide-out perforated cover in place. We recommend the
use of the cover even in console mounting for the addi-
tional shielding and protection it provides. The thickness
of the console panel may be up to 3/8".
a) Operations on console front panel preliminary to the
tuner 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
tuner mounting shelf. (2) Use an awl or anail to pierce
the centers of the two 3/8" diameter holes for the controls,
and the two small holes for mountingthe control plate, to
transfer their locations to the console panel beneath. (3)
Use ai awlornail to mark thefour corners of the rectan-
gular tuning dial cut-out. (4) Remove the panel template
and draw the dial cut-out with apencil. (5) Drill only
the holes for the panel controls (the two small holes which
have been marked are for wood screws). (6) Now make
the dial cut-out, which must be done accurately. It is
recommended that the rough cut-out be made slightly
undersize and then finished accurately aid smoothly with
afile. Then use the file to make asnioothly finished 45
degrees bevel on the lower edge of the cut-out sloping
downward from the outside surface to the inside surface.
The beveled surface must be smooth so that the wire going
to the tuning eye socket will not catch or otherwise be
obstructed when the tuning eye is moved along the dial.
b) Tuner mounting in console: (1) Pull off the control
knobT (2) Remove the four screws that fasten the bezel
to the side pieces and remove the bezel, which is not
used in console mounting. (3) Remove the control plate,
which Is attached to the bezel by two screws and nuts.
(These may be discarded since they are unsuitable for
attaching the control plate to the console paiel and two
4x3/8 wood screws have been supplied forthis purpose.
)
(4) Fasten the control plate to the console panel wtth the
two *4 x3/8 wood screws. (5) If the rubber feet have
been inserted in the bottom plate, remove them. (They
may be pried out with athin screwdriver. )(6) Place
the unit on the mounting shelf and slide it forward until
the front surface of the tuning dial rests against the turned-
in edge of the dial cut-out in the control plate and the
control shafts are centered in the holes. (7) With asharp
pencil, draw the outline of thesldeand rear bottom edges
on the chassis shelf. As the bottom pi ate fa] Is short of the
full width by 3/16" on eachslde, drawnew side edge Itnes
3/16" inside the original side edge lines. (8) Now fake
the chassis off the shelf. (9) Remove the 6screws which
fasten the bottom plate to the side pieces. (10) Place
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