Heathkit HD-1250 - Injection Mode of Operation; Mode of Operation

Page
42
OPERATION
NOTE:
Specific
uses for
your Solid-State
Dip Meter
are outlined in
the
"Applications"
section of this
Manual on Page
47. The fundamental
procedure
is
presented
in this
"Operation"
section.
IMPORTANT
NOTE:
You
should
always
observe
certain
precautions
when
you
use your
Dip Meter.
Some of
these
are:
1.
Protect
the
Dip
Meter from
strong
RF fields.
These
can damage
electronic
components
in the
Dip Meter,
even
when
the unit
is
turned off.
2. To conserve
batteries,
keep the
unit turned
off
when it is
not in
use.
3. Use only
magnetic
or dynamic
headphones
with
your Dip
Meter.
4.
Do not
force
the main
tuning
dial beyond
the
tuning
capacitor
stop
points;
you will have
to recalibrate
the
instrument.
5.
Do not
use any
power source
other
than the
battery
type
recommended.
An electronic
power
supply
can cause
the Dip Meter
to
malfunction.
ICAUTION:
If
the
Dip Meter
coil
or case should
come in
contact
with high
I
|voltages
in
units
under test,
a severe
or fatal
shock may
result.
I
Each
of the
seven pickup
coils supplied
with
your
Solid-State
Dip
Meter is
color
coded
to match
a color band
on the
tuning
dial
of
the instrument.
When
you
know the
approximate
resonant
frequency
of
the circuit
to be tested,
find
that
frequency
on
one of
the dial
scales.
Note the
color of
the dial
scale.
Then,
locate
the coil
whose
color
matches
that dial
color.
Plug
the coil into
the coil
socket
on
the rear
of
the Dip Meter.
Figure
2-1 is
an illustration
which
shows
the Dip
Meter with
a coil installed,
prepared
for
a typical
operation.
INJECTION
MODE
OF
OPERATION
If
the
approximate
resonant
frequency
of
the circuit
under
test
is known,
select
the
proper
coil
and plug
it into
the coil
socket.
Then,
adjust
the Dip
Meter
in the
following
manner:
I.
Depress the
pushbutton
switch
to turn
the Meter
on.
Turn
the
OSC LEVEL
control
until
you obtain
a midscale
reading.
Rotate
the tuning
dial
through its
entire range
and
note that
there is
a noticeable
tapering
in the
meter level
at each
end of
the dial range.
This
is normal.