prevent detuning effects.
NOTE: When connecting directly
to
the
input
circuit, make
certain
that
there
is
no ,high
DC
voltage present.
Otherwise, connect a blocking capacitor,
0.05 uF
-100
pF, depending on the frequency.
3.3 Modulated Carrier, internal source
Set the mode switch at INT. MOD.
By tuning the receiver
to
the generator frequency,
or
vice
versa, an audio
tone
will be heard in
the
loudspeaker. An audio
voltmeter should be connected across the speaker terminals when
aligning the internal circuits. A
dummy
resistor with suitable
power rating can
be
used in place
of
the moving coil curing
the measurements.
It
is advisable
to
keep
the
RF
signal level
as
low
as
possible
in order
to
prevent overloading the transistors or
IC
in the circuit.
Excessive
input
voltage will cause AGC action
and/or
two
resonance points
to
appear and proper alignment
or
adjustment
is
impossible.
3.4 Modulated Carrier, external source
Set the mode switch at EXT, MOD.
Connect leads from an external audio generator
to
the
INPUT.
Frequencies
up
to
20kHz can be used for modulation.
The
audio
input
voltage should
not
exceed 0.5V; this is
to
pre-
vent
modulation distortion.
3.5 Unmodulated Carrier
Set the mode switch at EXT. MOD. There should be no
connection
to
the INPUT.
6
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