O.
Introduction
The Frequency Response
Tracer
Type
4712
is designed especially
for
quality
control of electro-acoustic devices. Together with one of the B & K Beat Fre-
quency Oscillators it makes possible fully automatic, easily operated test
systems, suitable
for
checking
the frequency response
of
microphones, loud-
speakers, hearing aids, tape recorders, audio-frequency filters etc. in the
frequency range 20-
20000
Hz. This range can be extended to 200 kHz by
means of a mixer stage
or
frequency dividers, see page
26
and
33
.
The frequency response
of
mechanical constructions may also be investigated,
if transducers are available
for
converting mechanical vibration into electrical
signals.
The frequency response
of
the
test
object
is displayed
for
visual inspection
on a large calibrated screen with a
logarithmic
frequency scale and selectable
logarithmic
or
linear amplitude scales.
Apart from typical
production
control
applications
the instrument will prove
useful
for
many laboratory purposes where components are investigated
for
amplitude/frequency response. The
Tracer
can not, however, be used on its
own as a frequency analyzer since
it
has no frequency selective properties.
It indicates the amplitude
of
the input signal as a function
of
the frequency.
The mechanical sweep
of
the B & K oscillators is achieved with a small
electrical motor, supplied with the
Tracer
. This
motor
is installed inside the
oscillator
and obtains its
power
from the
Tracer
.
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