BRUEL & KJAER 1017 User guide
Beat Frequency Oscillator Type 1017
i
..
,p:
·:.
0:
'.=:·.:
"~.
~~
-
~
·
A
beat
frequency
oscillator
which
will
meet
the
numerous
requirements
of
a
signal
source
for
electrical
and
electro-mechanical
measurements
at
low
frequencies
.
fhe
frequency
scale
is
logarithmic
and
covers
the
frequencies
from
2 c/s
to
2ooo
c/s. An
automatic
output
regulator
makes
external
control
of
the
output
voltage
possible.
BRUFJL
&KJJEK
Naarum, Denmark .
eye
80
05
00
.
~
BRUKJA,
Copenhagen
. Telex: 5316
88
1017
Beat Frequency Oscillator
Type 1017
NOVEMBER
1965
Contents
Page
1.
Description
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
General
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Oscillator
and
Mixer
Section
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
100
Hz
Reference
Signal
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Compressor
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Partial
Blocking
of
Frequency
Range
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Output
Amplifier
Section
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Output
Voltmeter
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Overall
Performance
of
Oscillator
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Power
Supply
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2. Control Knobs,
Terminals
and
Shafts
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11
3. Operation
........................................................
14
General
..........................................................
14
A.
Initial
Setting
Up
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
B.
Frequency
Calibration
.........................................
14
C.
Use
of
Output
Terminals
marked
LOAD
........................
15
D.
Use
of
ATTENUATOR
OUTPUT
................................
15
E.
Partial
Blocking
of
Frequency
Range
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
15
F.
Remote
Control
Facilities
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
G.
To
Use
the
Compressor
Circuit
................................
17
H.
Use
of
the
100
Hz
REF
.
SIGNAL
..............................
18
I.
Use
of
Frequency
Increment
Scale
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.
Combined
Units
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Automatic
Frequency
Recorder
Type
3307
..........................
19
Automatic
Frequency
Recorder
Type
3328
..........................
20
5. Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Electrical
Measurements
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Amplifiers
and
Filters
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Frequency
Response
of
Filter
Circuit
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Low
Frequency
Measurements
on
Amplifiers
........................
25
Frequency
Range
of
High
Quality
Amplifiers
. . . . . . . . . . . . . . . . . . . . . . . . 26
Mechanical
Measurements
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Control
of
Vibration
Exciters
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
6.
Specifications
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Description
General.
The
Beat
Frequency
Oscillator
Type
1017 is
designed
as
a
low
frequency
signal
generator
covering
a
range
from
2-2ooo
Hz.
It
is
an
instrument
suit-
able
for
accurate
measurements
in
the
fields
of
acoustical
and
electro-
mechanical
research
and
design.
The
1017
employs
the
heterodyne
principle
as
the
generating
system
and
consists
of
two
audio
frequency
oscillators,
one
of
which
operates
on
a
fixed
frequency
and
the
other
on
a
frequency
which
can
be
varied.
The
output
of
the
two
oscillators
are
fed
to
a
mixer
and
the
difference
frequency
of
the
two
is
passed
via
a
low
pass
filter
to
an
output
amplifier
stage.
Impedance
Fixed Variable
JJ
Low Pass
Output
Matching
Oscillator
Amplifier
Mixer
Filter
Amplifier
Circuit
Load
Output
Regulating
Amplifier
Attenua.tor
Output
Variable Magnetic Output
Oscillator
Clutch
Attenuator
f59366
Fig. 1.1.
Block
diagram
of
B.F.O. 1017.
A
large
circular
frequency
scale
is
provided
and
is
marked
logarithmically
in
Hz
from
2-2ooo.
The
frequency
control
knob
and
pointer
are
mounted
on
the
shaft
of
a
variable
air-dielectric
condenser
which
tunes
the
variable
oscillator.
The
control
knob
is
fitted
with
a
fine
tuning
arrangement
with
a
reduction
ratio
of
5 : 1.
In
order
to
obtain
extremely
accurate
frequency
selection
an
incremental
adjustment
is
embodied
in
the
fixed
oscillator
which
provides
for
a
frequency
variation
from
+5
to
- 5
Hz
of
the
frequency
to
which
the
instrument
is
set
by
the
main
scale.
3
Provision
is
made
for
the
calibration
of
the
main
frequency
scale
by
injecting
the
frequency
of
the
power
supply
into
the
meter
circuit
and
comparing
this
on
the
meter
with
the
oscillator
frequency
which
is
set
to
the
power
supply
frequency.
For
calibration,
coarse
and
fine
frequency
adjustment
controls
are
provided
on
the
front
panel
of
the
instrument.
The
injected
power
supply
frequency
used
during
frequency
calibration
does
not
appear
at
the
output
terminals
of
the
instrument.
A
worm
gear
on
the
main
tuning
capacitor
drive
permits
automatic
tuning
of
the
B.F.O.
from
an
external
motor
drive.
The
worm
gear
can
be
engaged
and
released
by
an
electromagnetic
clutch
which
is
operated
from
a
switch
on
the
front
panel.
The
clutch
is a
friction
device,
and
provides
for
manual
tuning
of
the
variable
capacitor
even
when
the
worm
gear
is
engaged.
Provision
for
the
remote
control
of
the
clutch
is
made
at
the
socket
marked
REMOTE
CONTROL
on
the
front
panel.
Facilities
are
provided
for
regulation
of
the
output
voltage
of
the
instrument
by
means
of
a
feedback
loop
(COMPRESSOR
circuit).
Any
suitable
AC
voltage
source
may
be
coupled
to
the
compressor
input,
but
the
compressor
circuit
is
designed
to
be
controlled
by
the
signal
derived
from
the
B.F.O.
output
via
a
transducer
which
is
driven
by
the
B.F.O.
In
this
manner
it
is
possible
to
keep
a
voltage,
current
or
some
other
physical
quantity
constant
during
measurements.
Oscillator
and
Mixer Section. Fig.
1.1
shows
a
block
diagram
of
the
complete
B.F.O.
The
dotted
line
divides
the
diagram
showing
the
separation
between
the
oscillator/mixer/regulator
and
the
output
amplifier
sections
respectively.
The
fixed
oscillator
is
tuned
to
12
kHz
and
the
output
voltage
is
fed
to
the
grid
of
a
pentode,
the
bias
of
which
is
controlled
by
the
rectified
output
voltage
from
the
regulating
amplifier.
The
output
voltage
developed
across
the
grid
circuit
of
the
variable
oscillator
is
fed
to
the
input
of
a
buffer
amplifier
stage.
The
output
voltage
from
this
buffer
amplifier
is
supplied
to
the
mixer
stage.
The
frequency
of
the
variable
oscillator
is
continuously
adjustable
within
12
kHz
to
10
kHz.
The
tuning
is
obtained
by
a
spectaily
designed
variable
capacitor,
which
is
manufactured
to
a
high
degree
of
accuracy.
It
provides
a
frequency
scale
which
deviates
less
than
o.7
degrees
from
a
theoretical
logarithmic
scale.
In
the
mixer
tube,
the
output
voltage
from
the
fixed
oscillator,
derived
via
the
variable-~
amplifier,
is
mixed
with
the
output
voltage
from
the
variable
oscillator.
A
low-pass
filter
with
a
cut-off
frequency
of
5
kHz
is
inserted
in
the
anode
circuit
of
the
mixer
tube
to
allow
only
the
difference
frequencies
of
the
mixer
to
pass
to
the
output
amplifier
section.
100Hz
Reference Signal.
The
main
scale
is
set
on
the
100
HZ
REF.
SIGNAL
and
when
the
pushbutton
marked
100
HZ
REF.
SIGNAL is
depressed
the
4
resonance
circuit
of
the
variable
oscillator
is
paralleled
by
a
fixed
capacitor
and
there
will
be
a 100
Hz
output
signal.
In
this
way
it
is
possible
at
the
same
time
to
align
the
B.F.O.
with
the
fre-
quency
calibrated
paper
when
the
Level
Recorder
Type
2305 is
used,
and
to
check
the
signal
level
at
100 Hz,
because
of
the
distance
from
the
100 Hz Ref.
signal-mark
to
the
beginning
of
the
frequency
scale
(2
Hz) is
the
same
as
the
distance
on
the
paper
between
"10"
and
"20"
when
the
automatic
scanning
is
used.
Compressor
(Signal
Regulator).
The
object
of
this
circuit
is
to
control
the
output
of
the
B.F.O.
by
a
control
signal
derived
from,
for
example,
the
output
voltage
of
a
vibration
pick-up
mounted
on
a
vibration
table
which
is
excited
by
the
B.F.O.
By
this
method
the
acceleration,
velocity
or
displacement
of
the
vibration
table
can
be
kept
constant.
To
obtain
a
high
degree
of
regulation
the
working
point
of
the
variable-,u
pentode
is
chosen
on
the
non-linear
portion
of
its
Ia/Vg
characteristic
near
cut-off.
The
control
voltage
must
be
within
the
frequencies
given
by
LOWER
LIMITING
FREQ.
HZ, (2, 6, 20
or
60
Hz
and
2ooo
Hz).
The
lower
limits
are
indicated
by
the
COMPRESSOR
SPEED
position.
The
voltage,
which
should
be
of
approximately
1 V
or
higher,
is
fed
in
via
the
screened
socket
marked
COMPRESSOR
INPUT,
on
the
front
panel.
A
variable
potentiometer
marked
COMPRESSOR
LEVEL,
connected
in
the
input
circuit
of
the
regulating
amplifier
is
used
to
control
the
output
voltage
instead
of
the
OUTPUT
LEVEL
potentiometer,
which
should
be
in
its
maximum
position
when
the
compressor
circuit
is
in
use.
Under
these
conditions
the
COMPRESSOR
LEVEL
control
is
adjusted
to
a
position dependent
on
the
amount
of
com-
pression
or
voltage
output
required.
Turning
this
control
in
a
counter-clock-
wise
direction
increases
the
output
voltage
and
decreases
the
degree
of
com-
pression.
When
the
control
is
turned
fully
clockwise
(on "10")
the
signal
applied
to
COMPRESSOR
INPUT
is
fed
to
the
compressor
amplifier
without
any
attenuation.
The
amplified
control
voltage
is
rectified
in
a
full
wave
rectifier,
designed
to
give a DC
output
voltage
approximately
proportional
to
the
average
value
of
the
control
voltage,
which
is
an
advantage
when
the
control
voltage
is
not
a
pure-sine-wave.
The
speed
of
regulation
can
be
varied
by
means
of
the
switch
marked
COMPRESSOR
SPEED
which
changes
the
time
constant
of
an
R-C
filter
network
in
the
rectifier
circuit.
Compressor
speeds
of
3, 10, 30
and
100 dB/sec.
can
be
chosen.
A
special
circuit
has
been
included
which
precharges
the
capacitors
in
the
compressor
rectifier
circuit
before
they
are
switched
in.
In
this
way
no
un-
desired
change
in
the
B.F.O.
output
voltage
takes
place
when
the
COM-
PRESSOR
SPEED
switch
is
operated.
However,
the
circuit
enables
only
the
capacitor
next
lowest
in
the
compression
speed
sequence,
to
which
the
COMPRESSOR
SPEED
switch
is set,
to
be
charged
to
a
voltage
level
equal
to
that
of
the
capacitor
actually
in
use
.
It
is
therefore
necessary,
where
the
5
+30
Full
Indicating
Meter
deflecting~
~20
Graduation of
dB-·L
·1:
~
al
.....
0
Q.l
01
0
.....
0
>
.....
::3
a.
.....
-10
-20
-30
-40
-50
g
-60
L
-70
--
-
1--
--
.....
\
!--"
Distorted Signal
'·
\
l..4-
\
\\
1\
" I\
\\
Maximum
\ dynamic -
1--
1--
range of
" Compressor
"OUTPUT
LEVEl:'\
-
control
turned
j
~
~
down 0
dB
~-
-1-
-10
dB
-==-
-30
dB
----
~
-50
dB
""-
----
~
~
~
\II
i'-
1-'-
Noise-
1\~
~
1--
>Level
of B.
F.a
.
7 6 5 4 3 2 1 - 0 +1 2 3 4 5
dB
/622&0
Approx. 1V
L +
Relative variation of "COMPRESSOR
INPUT"voltage
Fig. 1.2.
Typical
compressor
characteristics
at
four
different
settings
of
OUTPUT
LEVEL
potentiometer.
COMPRESSOR
SPEED
is
decreased
during
operation
of
the
B.F.O.,
to
leave
the
COMPRESSOR
SPEED
switch
for
a
certain
period
of
time
(10-15
seconds)
in
each
position
before
it
is
switched
to
its
next
position.
When
the
compressor
is
fed
with
the
signal
from
the
B.F.O.
via,
for
example,
a
transducer,
i.e. a
direct
loop
system
is
used,
it
should
be
noted
that
at
low
frequencies
the
choice
of
too
high
a
re
g
ulation
speed
will
result
in
distortion
of
the
B.F.O.
output
signal
because
the
regulating
amplifier
in
this
case
tries
to
control
the
signal
wave
shape
itself
instead
of
the
output
level.
The
6
lowest
frequency
at
which
a
particular
compressor
speed
should
be
used
is
indicated
around
the
COMPRESSOR
SPEED
switch
(distortion
limit
approx.
2
%).
High
pass
filters
in
the
compressor
input
circuit
make
the
regulation
arrange-
ment
insentive
to
undesired
,
very
low
frequency
variations
in
the
drive
signal,
such
as
those
produced
by
large
surges
in
the
power
supply
voltage
or
mechanical
interference
in
vibration
test
systems.
The
limiting
frequency
of
these
filters
for
frequency
independent
operation
of
the
cnmpressor
coincides
with
the
above
mentioned
LOWER
LIMITING
FREQUENCIES
as
marked
around
the
COMPRESSOR
SPEED
switch.
A
level
change
of
2 dB
in
the
input
signal
to
the
regulating
amplifier
results
in
a
change
of
approximately
45 dB
in
the
B.F.O.
output
voltage.
In
other
words,
the
output
level
from
a
transducer,
fed
by
the
B.F.O.,
can
be
kept
constant
to
within
2 dB
when
the
variation
in
level
transfer
through
the
transducer
is
within
45 dB.
See
Fig.
1.2
where
the
regulation
characteristic
is
illustrated.
The
compressor
circuit
can
be
switched
off
by
means
of
a
separate
"On-Off"
switch.
To
ensure
good
regulation
at
all
output
levels
the
voltage
from
the
fixed
oscillator
is
raised
approximately
10 dB
when
the
automatic
regulation
is
switched
on.
A
band-pass
filter
in
the
form
of
two
inductively
coupled
circuits
is
inserted
in
the
anode
circuit
of
the
variable-,u
pentode
amplifier
to
prevent
any
unwanted
harmonics
generated
by
the
non-linearity
of
the
variable-,u
circuit
from
reaching
the
mixer
stage.
Partial
Blocking
of
Frequency
Range.
As
previously
mentioned,
the
frequency
scale
is
logarithmic
and
calibrated
2-2ooo
Hz.
When
the
capacitor
is
set
to
frequencies
above
2ooo
Hz
or
below
2
Hz
the
fixed
Oscillator
can
be
blocked,
and
consequently
no
output
voltage
will
be
obtained.
For
automatic
recording
of
frequency
characteristics,
i.e.
when
using
the
Level
Recorder
Type
2305,
this
is a
great
advantage
as
no
unwanted
curves
will
then
appear
on
the
corresponding
section
of
the
fre-
quency
calibrated
paper
.
The
cut-off
section
can
be
made
wider
by
adjusting
the
cam
discs,
connected
to
the
rear
end
of
the
capacitor
spindle.
However,
if
the
REMOTE
CONTROL
plug
is
removed
there
will
be
no
blocking
at
any
part
of
the
scale.
In
application
where
the
B.F.O. is
employed
in
conjunction
with
the
B & K
Level
Recorder,
and
where
automatic
recording
is
required,
the
blocking
arrangement
can
also
be
used
for
remote
lifting
of
the
Level
Recorder's
writing
pen.
This
is a
great
asset
in
for
example
measurements
where
the
compressor
circuit
of
the
B.F.O. is
used.
In
this
instance
the
pen-lifting
arrangement
of
the
Level
Recorder
can
be
controlled
from
the
frequency
blocking
circuit
by
making
the
appropriate
connections
to
the
REMOTE
CONTROL
jack
of
the
B.F.O.
In
cases
where
the
entire
frequency
range
(
2-2ooo
Hz)
of
the
B.F.O. is
utilized,
the
normal
frequency
blocking,
which
functions
outside
the
scale
graduation,
should
be
set
out
of
operation.
The
7
writing
pen
of
the
Level
Recorder
can
now
be
lifted
fro~
the
paper
outside
the
freque~cy
range
of
interest
and
a
proper
working
of
the
compressor
also
at
the
initial
frequency
(2
Hz)
is
ensured
during
the
automatic
scan.
If
the
described
method
is
not
utilized,
the
following
would
take
place:
No
signal
will
be
present
in
the
range
2ooo
Hz
to
2
Hz
(outside
the
scale
graduation).
The
compressor
of
the
B.F.O.
will
be
in
such
a
condition
that
when
the
scale
pointer
goes
inside
the
scale
graduation
(2
Hz)
full
output
level
will
not
be
transmitted
at
2
Hz,
and
after
the
chosen
time
delay
(Compressor
Speed}
the
signal
level
will
rise
to
the
proper
(preset)
value.
A
deflection
on
the
recording
paper
which
is
not
a
response
of
the
measured
object
would
thus
be
recorded.
Output Amplifier Section.
The
voltage
from
the
low
pass
filter
is
fed
to
the
control
grid
of
the
first
tube
in
the
two
-
stage
output
amplifier
via
a
variable
potentiometer,
which
is
used
to
control
the
output
level
of
the
instrument,
when
the
compressor
circuit
is
not
in
use.
This
potentiometer
is
marked
OUTPUT
LEVEL
on
the
front
panel.
The
gain
of
the
amplifier
is
stabilized
to
a
suitable
degree
by
means
of
a
voltage
negative
feedback
circuit.
In
order
to
overcome
the
use
of
heavy
and
large
sized
components
(un-
fortunately
necessary
at
low
frequencies),
the
output
stage
has
been
designed
as
a
single-ended
push-pull
circuit
using
two
EL86
tubes
or
their
equivalents.
Output Circuit.
The
output
circuit
is
coupled
to
an
impedance
matching
circuit,
employing
an
auto-transformer
as
matching
device.
This
provides
four
different
output
impedances
that
can
be
selected
with
the
switch
on
the
front
panel
marked
MATCHING
IMPEDANCE.
The
different
settings
of
the
switch
indicates
"6
0",
"60
lJ",
"600
lJ"
and
"6000
lJ"
respectively.
It
should
be
noted
that
the
actual
output
impedance
of
the
B.F.O.
is
10.-20%
only
of
the
indicated
values,
but
with
a
loading
corresponding
to
the
indicated
value,
maximum
power
output
is
obtained
with
a
minimum
of
harmonic
distortion.
The
output
voltage
from
the
auto
-
transformer
is
available
at
the
output
terminals
marked
LOAD,
the
right
hand
terminal
of
which
is
grounded.
A
fifth
position
of
the
MATCHING
IMPEDANCE
switch
is
marked
"Att.".
In
this
position
it
connects
the
output
of
the
amplifier
to
an
attenuator
with
10
steps
of
10
dB
providing
output
voltage
values
from
120 p,V
to
12 V.
This
variable
attenuator
switch
is
marked
ATTENUATOR,
and
the
output
is
con-
nected
to
the
screened
socket
at
the
top
right
hand
side
of
the
front
panel.
The
output
impedance
of
the
attenuator
circuit
is
approximately
50 Q
and
is
constant
over
the
entire
frequency
range.
Output Voltmeter.
The
voltage
at
the
output
terminals
of
the
instrument
is
indicated
by
a
vacuum
tube
voltmeter
which
measures
the
average
value
of
the
output
8
voltage.
It
is
calibrated
in
RMS
values
of
a
sinusoidal
voltage
with
an
accuracy
better
than
1 %
of
full
scale
deflection.
The
sensitivity
of
the
voltmeter
is
automatically
changed
when
the
position
of
the
switch
marked
MATCHING
IMPEDANCE
is
changed.
Full
deflection
of
the
meter
corresponds
to
the
value
indicated
by
the
switch
position.
To
obtain
a
well
defined
meter
reading
at
low
frequencies
as
well
as
at
high
frequencies
two
different
meter
damping
characteristics
can
be
chosen
by
means
of
a
switch
marked
METER
DAMPING
on
the
front
panel
of
the
instrument.
When
measurements
are
to
be
made
at
the
lower
frequencies,
the
switch
should
be
set
in
the
"Max."
position
and
at
higher
frequencies
in
the
"Min."
position.
Overall Performance
of
Oscillator.
Non-Linear Distortion.
The
harmonic
distortion
of
the
B.F.O. is
dependent
on
frequency
and
the
setting
of
the
OUTPUT
LEVEL
potentiometer.
The
distortion
increases
for
increasing
output
voltage
and
output
power.
Actual
and
guaranteed
distortion
will
be
as
illustrated
in
Fig.
1.3.
OJo
I I I
II
Harmonic
distortion
~\
= Typical
Distortion
Curves
------
= Guaranteed Upper
Limit
2,00
1,75
~
~
~
~
,,
,,
\ \
~
\ '
\ '
\
\ \ 1
'\
'
\\\
\ \
\ \ 1
Watt
7l
\ \ ----
\ \
\
'r-..
\'
--
" \
---
--
-
~-\
-----
c.---
---~
~
'
~
t-.
\
~
,.....,-::::
I'
1,5
1,25
1,0
0,75
0,5
0,25
Att.10V
~
Frequency
I
0
2Hz
5
10
20
50
100
200
500
1000Hz 2000
IS9367
Fig. 1.3.
Typical
distortion curves
with
tolerance limits.
9
Signal
to
Noise
Ratio.
The
signal
to
noise
ratio
of
the
B.F.O. is
better
than
70
dB
for
maximum
output
voltage.
By
noise
is
here
meant
the
self
induced
noise
plus
the
spurious
frequencies
and
the
hum
from
the
B.F.O.
Oscillator
Stop.
A
"click-free"
OSCILLATOR
STOP
push
button
is
provided
for
momentary
interruption
of
the
oscillator
output.
When
the
button
is
pressed
with
the
automatic
regulation
circuit
in
operation
,
the
capacitors
in
the
compressor
rectifier
circuit
remain
charged.
Owing
to
this,
no
sudden
increase
in
oscillator
output
voltage
will
occur
on
its
release.
Remote
Frequency
Scale
Scanning.
The
Frequency
Main
Scale
can
be
remotely
scanned
via
a
mechanical
drive.
The
arrangement
is
intended
to
be
driven
from
the
B & K
Level
Recorder
Type
2305
via
the
Flexible
Shaft
UB
0041
(1
meter).
In
this
manner
the
frequency
scan
of
the
B.F.O.
can
be
driven
in
synchronism
with
the
pre-print
on
the
recording
paper
of
the
Level
Recorder.
The
built-in
worm
gear,
having
a
ratio
of
50:
1,
causes
a
scale
pointer
movement
through
one
octave,
when
turning
the
input
drive
of
the
B.F.O.
three
revolutions.
Power
Supply.
The
1017 is
designed
to
operate
from
a
supply
of
240 ,220, 150, 127, 115
or
100
volts
AC, 50
to
400
Hz
with
a
power
consumption
of
approximately
90
watts
.
The
B.F.O. is
set
to
the
appropriate
power
line
voltage
by
a
selector
which
is
combined
with
a
fuseholder
and
located
on
the
rear
of
the
instrument.
For
setting
see "
Operation".
The
primary
side
of
the
power
supply
transformer
is
protected
by
a
fuse
placed
in
the
combined
mains
voltage
selector
and
fuseholder
.
J()
2.
Control
Power
Power Frequency
Beat
Compressor Speed
Knobs, Terminals and Shafts
Load
Level
Oscillator Stop Remote Control Compressor
Ref
.
Signol
Frequency
Scale
Alignment
165(20
Fig. 2.1.
Front
view
of
B.F.O. 1017
showing
identification
of
controls,
terminals
etc.
POWER:
METER
DAMPING:
POWER
FREQUENCY
BEAT:
When
switched
to
"On"
the
meter
scale
and
fre-
quency
scales
will
be
illuminated.
"On",
the
indicating
meter
is
electrically
damped.
To
be
used
at
the
lower
frequencies.
Pushbutton,
when
pressed
and
held
in, a
beat
be-
tween
power
supply
frequency
and
output
fre-
quency
of
the
B.F.O.
can
be
observed
on
the
in-
dicating
meter.
By
this
arrangement
the
output
frequency
can
be
brought
to
coincide
with
the
calibration
of
the
Frequency
Main
Scale.
11
AUTOMATIC
SCANNING:
Shaft
Connection
for
Mechanical
Drive:
FREQUENCY
MAIN
SCALE:
FREQUENCY
INCREMENT:
COMPRESSOR
SPEED:
OSCILLATOR
STOP:
REMOTE
CONTROL:
COMPRESSOR:
REF.
SIGNAL:
FREQUENCY
SCALE
ALIGNMENT:
12
"On"
and
"Off".
For
controlling
the
electromagnetic
friction
clutch
in
the
mechanical
remote-frequency-
scanning
system.
For
connection
of
Flexible
Shaft
UB 00'41
when
remote
frequency
scan
of
the
B.F.O. is
provided
from
the
B & K
Level
Recorder
Type
2305.
Logarithmic.
Indicates
the
output
frequency
when
the
B.F.O. is
frequency
calibrated
by
the
Power
Frequency
Beat
arrangement
and
Frequency
Incre-
ment
Scale
is
set
to
"0'".
For
exact
variation
(max. ± 5 Hz)
of
the
output
frequency
as
set
on
the
Frequency
Main
Scale.
"3",
"10",
"30"
and
"100"
dB/sec. gives
the
regula-
tion
speed
of
the
compressor
circuit.
The
"Lower
Limiting
Freq."
2, 6, 20
and
60
Hz
indicated
together
with
the
speeds,
gives
the
lower
limiting
frequencies
at
which
the
non-linear
distor-
tion
of
the
output
signal
is
approximately
2 %
at
the
respective
compressor
speed
used.
Pushbutton;
when
pressed,
the
output
signal
of
the
B.F.O. is
interrupted.
The
anode
voltage
of
the
fixed
oscillator
is
disconnected
via
a
relay.
For
external
connections
when
remote
control
of
the
electromagnetic
clutch
and
Oscillator
Stop
is
desired.
"On".
In
this
position
the
compressor
is
switched
in
circuit
and
the
output
voltage
of
the
B.F.O. is
increased
by
10
dB.
Pushbutton;
when
pressed,
the
output
signal
fre-
quency
will
change
to
100
Hz,
assuming
the
Fre-
quency
Main
Scale
has
been
set
to
100
HZ
REF.
SIGNAL
and
the
Frequency
Increment
Scale
is
on
"0".
To
be
used
for
Frequency
calibration
of
the
B.F.O.
"Coarse",
screw-driver
operated,
has
to
be
used
when
the
range
of
"Fine"
is
not
sufficient.
OUTPUT
LEVEL:
COMPRESSOR
INPUT:
COMPRESSOR
VOLTAGE:
Load:
MATCHING
IMPEDANCE:
OUTPUT
ATTENUATOR:
ATTENUATOR
Linear,
wire
wound,
continuously
variable
potentio-
meter.
Is
located
at
the
input
of
the
output
ampli-
fier,
thus
affecting
both
the
outputs
LOAD
and
ATTENUATOR
OUTPUT.
The
regulation
voltage
can
be
attenuated
by
the
potentiometer
COMPRESSOR
VOLTAGE.
Logarithmic
potentiometer
for
attenuation
of
re-
gulation
voltage
on
COMPRESSOR
INPUT.
Terminal
set
presenting
various
output
impedances.
Refer
also
to
item
MATCHING
IMPEDANCE
below.
The
right-hand
terminal
is
grounded.
"6
£2",
"60
£2",
"600
.Q"
or
"6ooo
£2"
load
can
be
connected
in
the
respective
positions.
The
actual
output
impedances
are
10'--20 %
of
the
stated
values.
The
voltages
indicated
by
MATCHING
IMPEDANCE
are
the
RMS
voltages
obtainable
in
the
respective
positions
for
full
meter
scale
de-
flection.
"A
tt.".
The
output
voltage
is
available
on
the
term
-
inal
ATTENUATOR
OUTPUT.
When
MATCHING
IMPEDANCE
is
set
to
"Att.",
the
output
signal
to
the
"Attenuator
Output"
can
be
attenuated
in
ten
accurate
steps
of
10 dB.
The
values
indicated
by
the
knob
positions
correspond
to
the
RMS mV
available
at
full-scale
indicating
meter
deflection.
OUTPUT:
Output
signal
available
when
MATCHING IM-
PEDANCE
is
in
position
"Att."
RMS
output
signal
voltage
is
read
on
the
indicating
meter
in
accord-
ance
with
the
position
of
the
OUTPUT
ATTEND-
TOR
switch.
INDICATING
METER:
For
indication
of
output
voltage.
Measures
the
average
value
but
is
graduated
to
show
the
R.MS
value
of
sine-wave
signals.
13
3.
Operation
General.
Firstly
ensure
that
the
instrument
is
adjusted
to
the
appropriate
power
supply
voltage.
If
not,
remove
the
fuse
on
the
rear
of
the
apparatus
and
turn
the
inner
part
of
the
combined
voltage
selector
and
fuseholder
by
a
coin
until
the
white
mark
points
to
the
desired
voltage.
After
replacing
the
fuse
the
apparatus
is
switched
on
with
the
switch
marked
"Power"
on
the
front
panel.
Immediately
the
meter
and
frequency
scales
should
light
up.
A.
Initial Setting Up.
Set
the
controls
on
the
front
panel
of
the
instrument
as
follows,
commencing
at
the
top
left:
1.
METER
DAMPING:
"Min.".
2.
AUTOMATIC
SCANNING:
"Off".
3.
FREQUENCY
INCREMENT:
"0"
Hz.
4.
COMPRESSOR
SPEED:
Any
position.
5.
REMOTE
CONTROL:
Plug
should
be
in
place.
6.
COMPRESSOR:
"Off".
7.
OUTPUT
LEVEL:
A
position,
say
"3",
to
give
a
mid-scale
deflection
on
the
meter.
8.
COMPRESSOR
VOLTAGE:
Any
position.
9.
MATCHING
IMPEDANCE:
Any
position.
10.
ATTENUATOR:
Any
position.
11.
Frequency
Main
Scale:
Pointer
set
to
any
part
of
the
printed
scale.
B.
Frequency
Calibration.
It
is
recommended
to
allow
a
warm-up
time
of
approx.
5
minutes,
after
which
the
frequency
scale
calibration
should
be
checked
as
follows:
1.
Set
Frequency
Scale
to
the
frequency
corresponding
to
that
of
the
power
supply.
The
fine
adjustment
knob
of
main
scale
pointer
is
operated
by
pressing
and
turning.
2.
Press
the
button
marked
POWER
FREQUENCY
BEAT.
3.
Adjust
the
"Fine"
control
knob
of
the
FREQUENCY
SCALE
ALIGN-
MENT
until
a
zero
beat
is
obtained.
If
the
adjustment
is
outside
the
range
of
the
"Fine"
control
this
should
be
set
to
midposition
and
the
"Coarse"
control
adjusted
with
a
screwdriver
to
bring
the
beat
to
approximately
zero.
The
"Fine"
control
is
then
used
to
obtain
the
zero
beat.
14
•
f
4.
Set
the
Frequency
Main
Scale
to
a
frequency
corresponding
to
~5
of
the
power
supply
frequency
and
repeat
item
2
and
3.
5.
Turn
the
Main
Scale
pointer
to
2
Hz
and
gradually
bring
the
FRE-
QUENCY
INCREMENT
reading
to
- 2
Hz.
If
the
frequency
calibration
above
has
been
done
at
the
proper
beat
the
indicating
meter
needle
will
drop
to
zero.
If
not,
readjust
FREQUENCY
SCALE
ALIGNMENT
to
obtain
zero
meter
deflection.
Thereafter,
reset
FREQUENCY
INCRE-
MENT
on
"0"
Hz
and
repeat
procedure
from
item
B.1
at
the
new
beat.
6.
The
B.F.O.
is
ready
for
use.
C.
Use
of
Output
Terminals
marked
LOAD.
With
the
instrument
set
up
as
in
A
and
B
above,
proceed
as
follows:
1.
Connect
the
object
under
test
to
the
LOAD
terminals,
the
right
hand
one
of
which
is
ground.
2.
Set
the
MATCHING
IMPEDANCE
switch
to
the
appropriate
impedance
value.
3.
Adjust
the
OUTPUT
LEVEL
control
to
give
the
required
drive
to
the
object
under
test.
4.
Select
the
test
frequency
with
the
pointer
knob
of
the
Frequency
Main
Scale.
D.
Use
of
ATTENUATOR
OUTPUT.
With
the
instrument
set
up
as
in
A
and
B
above,
proceed
as
follows:
1.
Connect
the
object
under
test
to
the
screened
output
socket
at
the
right
hand
op
of
the
panel.
2.
Set
the
MATCHING
IMPEDANCE
switch
to
"Att.".
3.
Set
the
ATTENUATOR
switch
to
the
appropriate
output
voltage
range.
Full
scale
deflection
on
the
meter
is
indicated
by
the
value
in
millivolts
on
each
of
the
switch
positions.
4.
Adjust
the
OUTPUT
LEVEL
control
to
give
the
required
output
voltage
within
the
range
selected
by
the
ATTENUATOR
switch
.
E.
Partial
Blocking
of
Frequency
Range.
The
initial
and
/
or
the
final
part
of
the
frequency
range
can
be
blocked
by
means
of
the
camdiscs
mounted
on
the
spindle
of
the
tuning
capacitor
(Fig.
3.1).
The
frequency
range
can
be
reduced
to
approximately
one
octave
in
any
part
of
the
frequency
range.
The
Blocking
range
is
adjusted
as
follows:
1.
Disconnect
the
instrument
from
the
power
supply
line.
2.
Remove
rear
plate
of
apparatus.
3.
Loosen
knurled
lock-nut
(Fig.
3.1)
sufficiently
for
the
outer
and
inner
cam
disc
to
be
moved
in
relation
to
the
one
in
the
middle.
Hold
back
the
dial
knob.
4.
Set
the
pointer
of
the
main
scale
to
the
lowest
frequency
of
the
desired
frequency
range.
15
5.
Turn
the
inner
cam
disc
to
the
right
(seen
from
behind)
until
the
contact
is
activated
by
the
cam
disc.
6.
If
necessary
tighten
the
lock-nut
so
much
that
the
cam
disc
is
not
dis-
placed
when
the
main
scale
pointer
is
moved.
7.
Set
the
main
scale
on
the
highest
frequency
within
the
desired
frequency
range
and
turn
the
outer
cam
disc
to
the
left
until
the
contact
is
activated.
Be
carefull
that
the
inner
cam
disc
does
not
move.
Cam
Discs
Knurled Nut
Fig.
3.1.
Cam
disc
arrangement
.
8.
The
cam
disc
in
the
middle
should
be
rotated
so
that
it
does
not
inter-
fere
with
the
frequency
range
in
use.
9.
Tighten
the
lock-nut,
still
being
carefull
that
the
cam
discs
do
not
move.
10.
Replace
the
rear
plate.
11.
Connect
the
apparatus
to
the
power
supply
line
and
set
POWER
switch
to
"On".
12.
After
a
few
minutes
warm
up
calibrate
as
described
in
B.
This
can
be
done
when
the
REMOTE
CONTROL
plug
is
removed.
13.
Replace
the
REMOTE
CONTROL
plug
and
set
the
main
scale
on
a fre-
quency
inside
the
desired
frequency
range.
14.
Turn
OUTPUT
'
LEVEL
to
a
suitable
deflection
of
the
meter.
15.
When
rotating
the
frequency
scale
pointer
over
the
entire
scale
there
will
be
a
signal
(meter
deflection)
only
inside
the
desired
frequency
range.
Note!
If
the
desired
frequency
blocking
does
not
occur
at
all
check
that
the
REMOTE
CONTROL
plug
is
well
home.
If
the
frequency
range
is
not
correct
start
procedure
over
once
again
from
E.l.
16
•
F.
Remote
Control
Facilities.
The
clutch
and
the
OSCILLATOR
STOP
controls
can
be
remotely
controlled
by
making
connections
to
the
remote
control
plug
on
the
front
panel
of
the
instrument.
Fig. 3.2
shows
the
connections
to
the
pins
of
the
socket.
When
the
clutch
is to
be
remotely
controlled
it
is
essential
that
the
AUTOMATIC
SCANNING is
first
set
to
the
"Off"
position.
When
the
remote
control
facilities
are
not
required,
the
pins
marked
c
and
d
plus
e
and
f
in
Fig. 3.2
must
be
short-circuited
in
the
plug,
which
must
then
be
in
place.
This
interconnection
is
already
taken
care
of
in
the
plug
supplied
with
the
instrument.
Internal
contact
e
Viewed
externally
Oscillator
stop
b
-24v
Ground Magnetic
clutch
a and
b:
To
remote
clutch
control
c and f :
To
remote
oscillator
stop.
165134-
Fig. 3.2. Connections
to
the
remote
control
plug.
Externally
viewed.
G.
To
Use
the
Compressor
Circuit.
Connect
the
instrument
to
the
circuit
to
be
excited
and
connect
the
feedback
control
circuit
to
the
COMPRESSOR
INPUT
socket.
Note! A
compressor
Input
voltage
of
at
least
1
volt
is
necessary
for
the
com-
pression
circuit
to
function
correctly.
Set
up
the
instrument
as
in
A,
B
and
C
or
A,
B
and
D
using
facility
E
if
required.
Proceed
as
follows:
1.
Set
COMPRESSOR VOLTAGE
to
"10".
2.
Set
OUTPUT
LEVEL
to
"0".
3.
Set
the
COMPRESSOR
SWITCH
to
"On".
4.
Set
the
COMPRESSOR
SPEED
knob
according
to
the
lowest
frequency
to
be
used.
See
also
Description
part
Compressor.
17
5.
Turn
the
OUTPUT
LEVEL
control
up
to
maximum,
taking
care
while
doing
so
that
the
meter
does
not
show
any
overload
deflection
exceeding
full
scale.
If
the
meter
does
show
a
continuous
overload,
this
indicates
that
there
is
either
a
faulty
connection
in
the
feed
back
loop
or
that
there
is
insufficient
feedback
voltage
(i.e.
less
than
the
necessary
1
volt
at
the
COMPRESSOR
INPUT).
In
either
case
return
the
OUTPUT
LEVEL
control
to
the
"0"
position,
set
the
COMPRESSOR
switch
to
"Off",
and
check
the
arrangement
for
any
possible
errors
of
malfunction.
6.
Adjust
the
output
voltage,
which
is
indicated
on
the
·
meter,
to
the
required
level
by
turning
the
COMPRESSOR
VOLTAGE
control
in
a
counter-clockwise
direction.
It
should
be
born
in
mind
that
by
raising
the
output
voltage
with
this
control
the
degree
of
compression
is
reduced
at
the
same
time.
H.
Use
of
the
100
Hz
Reference
Signal.
To
obtain
the
100
Hz
reference
output
signal
proceed
as
follows:
1.
Set
up
the
instrument
as
described
in
A,
B
and
C
or
A, B
and
D,
using
the
compression
circuit,
E,
if
required.
2.
Set
the
frequency
scale
pointer
to
100
HZ
REF.
SIGNAL.
3.
Press
the
button
marked
100
HZ
REF.
SIGNAL.
A
sig
,
nal
of
100
Hz
will
now
be
present
at
the
output.
The
signal
level
will
be
equal
to
that
obtained
when
simply
turning
the
Frequency
Main
Scale
pointer
to
"100"
Hz.
I.
Use
of
Frequency
Increment
Scale.
When
the
Frequency
Increment
Scale
pointer
is
set
on
zero,
"0",
the
signal
frequency
is
as
indicated
by
the
Frequency
Main
Scale
pointer,
assuming
that
the
B.F
.0.
is
adjusted
as
stated
in
item
B,
Frequency
Calibration.
By
using
the
Frequency
Increment
the
signal
frequency
can
be
changed
an
amount
of
± 5
Hz
in
relation
to
the
frequency
chosen
on
the
Frequency
Main
Scale.
18
j
Table of contents
Other BRUEL & KJAER Portable Generator manuals
Popular Portable Generator manuals by other brands
Tanaka
Tanaka DEG-600 Spare parts catalogue
Könner & Söhnen
Könner & Söhnen KS 2900 instructions
A-iPower
A-iPower DUAL FUEL Series owner's manual
EINHELL
EINHELL TC-PG 850/3 Original operating instructions
Generac Power Systems
Generac Power Systems 005802-2 owner's manual
cecotec
cecotec TOTALPURE 3000 SMART OZONE instruction manual
