Heathkit W-5M User Manual

Low or
high frequency
noise
in the
amplifier can
usually
be
traced to a
defective
resistor
or
a
faulty
tube.
The
troublesome
point
can
be
located
quickly
by
removing
tubes
one
at
a time
,
starting
with VI,
then
V2,
etc.
When
a
point
is
found
where
the noise
disappears,
the
trouble-
some
stage
has
been
isolated.
Further checks
should be
made
at
this
point
by
swapping
identical
tubes
or
replacing
them
to see
if the trouble will
clear up.
If
tube
replacement
fails to
help, one
of the
resistors
is
probably
noisy
or
a
poor
connection
exists
somewhere
in
the
circuit. Noisy
resistors
can
be
located
by
shorting out resistances
connected
to tube
sockets VI
and
V2,
start-
ing
with
the
input stage
and
working back as
far
as
pins
1
and 6
of
V2.
When
observing
this
pro-
cedure,
short out the
resistor
in
question, not between
each
pin of the
amplifier tube
socket
and
ground.
The
first point
at
which
the
noise
disappears
isolates
the defective
component. Hiss
or
high
frequency
noise
is
usually
caused
by a
defective
tube,
resistor
or connection. Hum
and
other types
of low
frequency
noise
is
frequently
due
to a
defective tube,
poor connections, ex-
cessively
long
leads
or
improper
lead
dress. When
checking
the
amplifier
components
with
the
unit turned
on,
observe
due
caution at
all
times.
Dangerously
high
voltages are
present
through-
out
the circuit.
INSTALLATION
AND
OPERATION
The
Heathkit
W-5M
Amplifier
readily
lends
itself to
practically
any
type of
installation. Large
rubber
feet are used
so
that the
unit can be
placed
anywhere
without danger
of
marring
furniture
and
it
will not slide
about
even
if not
bolted
down. For
permanent
installations,
the
unit can
be
fastened down
with
the
bolts and
T-nuts
furnished,
using
the
furnished
template
to cut the two
necessary
holes.
Use
the large
fiber washers
under
the bolt
heads
to
prevent
marring
the chas-
sis
finish.
Do
not
remove
the
rubber feet
if the
amplifier
is to be
bolted down,
since some
air
space
must
be
provided
between the
amplifier
and the
mounting
board for
ventilating purposes
.
When
the
amplifier
cover is
first
installed, it
will
probably
fit too tightly. It
should
not
be
pos-
sible to pick
the
amplifier up by
grasping
the
cover, since the
amplifier
might
be
released sud-
denly
causing
serious damage.
To
adjust
the
cover
tension, insert
a
screwdriver blade
between
the
springs
of
the catch
clips
and spread
them
slightly until
satisfactory
tension is
obtained.
Markings
on
the
front apron of the
chassis
are
self-explanatory. One
suggestion;
when connecting
the
preamplifier
to the
W-5M,
shielded cable
should
be
used,
terminating
in
a
standard phono
plug.
Full
instructions
for preparation
of
this
cable are
included with
the Heathkit
WA-P2
Pre-
amplifier
kit.
Brief instructions
are
included
here, should
other
equipment be used.
Follow
Figure
18 above
to
connect
the
phono
plug to
shielded
cable
which has
a
spirally
wrapped
shield.
Certain
cables
are
furnished with
braided
shields. In
such cases,
unbraid
the
shield
using
a
sharp
pick
or scribe,
until
sufficient
conductor is
available
for
connecting
to the
plug
shell.
Page
27

Heathkit W-5M Specifications

General

Brand	Heathkit
Model	W-5M
Category	Amplifier
Language	English