3. Set
Filter
C.ontrols
POWER'
"On"
SCANNING
"Manual"
Selective
Ranges
and 1/1 and
1/3
octave band switched in
as
desired.
FILTER
SWITCH
to
the
filter
at
which the measurements
are
to
be
carried
out.
4. The
two
ranges setting switches (upper switches) should
be
set
so
that
the meter
pointer
should
be
in the upper half
of
the
scales
and
the
outer
transparent
knob
should always
be
as
far clockwise
as
possible
to
give
the
best signal
to
noise ratio.
The
signal
within
the
chosen
filter
and referred
to
the
input
of
the
measuring arrangement
is
read according
to
the method described in the
Instruction
Manual
for
2203, 2204.
These
should also
be
referred
to
for
checking
of
the
battery
supplies.
For calibration
of
the
system
with
respect
to
B & K measuring transducer
refer
to
its
Instruction
Manual.
6.
USE
WITH F.M. TAPE RECORDER TYPE 7001
The F.M. Tape Recorder
Type
7001
has
a linear frequency range
from
DC
up
to
20
kHz depending on the tape
speed
employed. Using frequency
transformation techniques,
the
7001
and
1614
can
be
used
to
make very
low
frequency sound and vibration measurements. The 7001 contains a
voice
channel
to
allow
for
marking and identification
of
the tapes. A signal
from
a
440Hz
ref. generator can
be
recorded on the voice channel. The
440
Hz signal
can
be
used
to
control
the marker
unit
during playback. This
unit
can
control
the switching
of
the 1614/15 when frequency analysis
is
made
from
tape
loop
and recorded graphically
by
means
of
the Level Recorder
Type
2305. A synchronisation
can
be
obtained between the movement
of
the preprinted recording paper and the tape loop cycle. A requirement
for
such a synchronisation
is
that
the tape loop cycle must
be
longer than the
time
required
for
the recording paper
to
advance 1/3 octave.
Further
details
can
be
obtained
from
the Instruction Manual 7001.
7.
USE
WITH RANDOM NOISE GENERATOR TYPE 1402
1/3
and 1/1 Octave bands
of
noise
can
be
supplied
from
the Noise
Generator when
the
Filter
Sets Types 1614/15
are
inserted between the
microphone
amplifier
section via the
two
EXTERNAL
FILTER
terminals
of
the Noise Generator.
By
using this combination
of
the Noise Generator plus
Band-Pass
Filter
Set
the
characteristic
of
the. Noise;
signal
fulfils
among
other
28
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