Specifications

ManualsBrandsEico ManualsPortable Generator378

mechanical

installation

GENERAL

HEAT

DISSIPATION(VENTILATION): In common with

other

electronic equipment, the HF-81 produces consider-

able heat in normal operation. Unless continuous and

ade-

quate air flow isobtained 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 suitability of a location.

Air heated by the heat-producing elements expands and

rises; cool

air

is drawn from beneath to take the

place

the heated air. In this manner, a stream of

air

set

motion which continually removes heat from the

ampli-

fier. (In particular, we are mainly concerned with the

major heat-producing elements; the four EL84output tubes

and the two EZ81 rectifier tubes.) If there is any impedi-

ment to or constriction of the airflow, the essential process

of heat removal will be adversely affected.

Adequate ventilation will be provided if the amplifier is

installed in an

open-back

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 back 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

~ff~~ti~e

ve~tiiation

requires

provis~n

for cooi air to

en-

ter at the bottom and hot

air

to leave at the top.

]f the amplifier is not installed in a console, it may be

situated on an open surface or on a shelf of a bookccse,

Four rubber feet are also provided so that the amplifier will

not

mar the surface of furniture on which it is

placed.

EASY

ACCESS

TO CONTROLS: Mount the amplifier

at a height which will permit easy manipulation of the

con-

trols. Tuner controls should be located nearby.

ACCESSIBILITY

PARTS:.

Tubes are the most

fre-

quently replaced items in

electronic

equipment. If the

amplifier is installed in a console, sufficient space should

be alloted 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 portable tape recorder which is stored

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 sufficient separation to minimize mechanical speaker

vibration reaching the amplifier. The minimum separation

is about one foot.

CONSOLE

MOUNTING

a) 0 erationson console front anel reIiminar to am

Ii-

fier mounting: 1 Tape the panel template provided to

the face of the console so that the top of the mounting

sur-

face line on the template is level with the top of the

amplifier mounting shelf.

Note:

When shelf is not

avail-

able, tape the template at any convenientspot on the face

of the console. (2) Use an awl or a nai I to pierce the

centers of the four extreme outer holes for mounting the

control plate)' to transfer their locations to the console

panel beneath. (3) Trace out the rectangular cutout with

an awl or nail and then pierce the centersof 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

con-

sole panel, one in

each

corner of the rectangular cutout

area.

Cut out the rectangular

piece

with a keyhole

saw)'

using the four 1/2" holes as starting holes.

b) Am Iifier mounting in console: (1) Pull off the control

knobs. 2

Remove

the four screws that fasten the bezel

to the side pieces and remove the

bezel.

{3}

Remove the

two screws and nuts that fasten the control plate to the

bezel.

The bezel is not used in console mounting.

Fasten the control plate to the console panel with the two

#4x3/8

woodscrews supplied. (5) If the rubber feet have

been inserted irwhe bottom plate)' remove them. (Theymay

be pried out with a thin screwdriver.) (6) Place the unit _

on the mounting shelf and slide it forward until the slide

_ •

__.

t I I

switch support bracket is up against the panel and the

slide switch accessible fromthe front; the control shafts

should be approximately centered in the corresponding

holes in the control

plate.

(7) With a sharp pencil, draw

the outl ine of the side and rear bottom edges on the chassis

shelf.

the bottom

plate

falls short of the full width by

3/16"

each

side)' draw new side edge lines

3/16"

in-

side the original side edge lines. (8) Now remove the

knobs and take the chassis off the shelf. (9) Remove the

6screws which fasten the bottom

plate

to the chassis. (10)

Place the bottom plate

exactly

in the outl ine drawn 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) Refasten the bottom

plate

to the chassis, with the four of the

six#8x3/8screws

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 indicator dot on

each

knob agrees with the

control position. (14) From the bottom side of the shelf,

insert a #8 x I" 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 and when tightened secure the chassis

to the shelf.