Absorption Wave Meter Mode Of Operation - Heathkit HD-1250 Manual

HD-1250
Figure 2-3
Page
45
ABSORPTION
WAVE
METER
MODE
OF OPERATION
CAUTION: When
you use the
Dip Meter near energized
RF
circuits, start
with
the
Dip Meter
some
reasonable distance
away from
the circuit to avoid
overdriving the
meter
circuits.
Adjust the
Dip Meter
in
the following manner:
1
.
If
possible, select a coil
whose frequency range
will
cover that of the
unknown
circuit.
For example, the
IF
frequency
in
FM
circuits will
be
at
or near 10.7
MHz.
If
the circuit
under
test
were
in
a stereo IF
circuit, logically
the yellow
coil
would be used
to
make
the
test,
since the range of the coil
is
6.3 to
13
MHz.
Plug the
coil into
the
coil
socket.
2.
Press the
pushbutton
to turn
the Dip Meter On.
3.
Turn
the
OSC LEVEL
control to obtain a midscale reading
on the
meter.
4.
Turn the tuning
dial
from one extreme to the other
and
note the
taper of the reading at
both ends of the
dial.
Select
the very
highest
reading possible;
then
leave
the tuning
dial set
at
that point.
5.
Carefully turn the
OSC LEVEL
control to
reduce the meter reading
just
to the zero point.
Leave the
OSC LEVEL
control
at this setting.