
BROEL
&
KJ.ER
Ncerum
-
Denmark
Removal
of
Tuning Capacitor CV 0009.
Oscillator
Valid
from
serial
no.
170230
1008.2
Remove the right hand side cover (when seen
from
the instrument front
plate)
of
the
capacitor
unit CV 0009.
Set the condenser to fully "turned in" position .
The
posi.tion
of
the condenser
is
checked with a
plate
of
insulating
material,which
strokes over the.stator plates, so
that
none
of
the rotor plates
is
above the stator
plates.
The
scale
pointer should naw point
at
220°.
If
not,
note carefully dawn the position
of
the pointer.
Remove
the multi-plugs and unsoldering the two leads to the oscillator coil
assembly. Unscrew the two knobs on the tuning spindle and remove the
scale
rim, pointer and
scale.
The
four screws, which secure
Tuning Capacitor CV 0009 to the front
plate,
can then
be
unscrewed
Replacing Tuning Capacitor _CV 0009.
After replacing
scale,
center
it
with reference to the spindle by means
of
a centering bush. Check
the
position
of
the condenser
with a
plate
of
insulating material
for
fully interleaved
capacitor
plates and fix the pointer to 220° or
to
the position noted
above.
Attention: Item 2.
1.
and 2.
2.
The
frequency
can
only be checked by means
of
a frequency counter or a frequency standard and an
---
oscilloscope.
The
voltage should
be
measured by means
of
a high impedance (law
capacity)
tube voltmeter.
D-r---t--+---+--1_
c
---4-+-+-+--+-4
C133~~~~~~;;==ril
Output 30 kHz and 35 kHz bottom view
2.1.
Fixed
Oscillator.
a.
FREQUENCY RANGE: "5005-10ooo
Hz"
b.
FREQUENCY
RANGE
to "5-5ooo Hz"
c.
METER
SWITCH: "Output Voltage"
SCANNING
SWITCH:
"Off"
FRfQUENCY RANGE: "5-5000 Hz"
COMPRESSOR
SPEED:
"Off"
OUTPUT
SWITCH:
"Linear"
FREQUENCY
SCALE:
"10Hz"
2.2.
Variable
Oscillator.
a.
METER
SWITCH:
"Output
Voltage"
SCANNING
SWITCH:
"Off"
FREQUENCY RANGE: "5-5ooo Hz"
COMPRESSOR
SPEED:
"Off"
OUTPUT
SWITCH: "Linear"
FREQUENCY
SCALE:
"5Hz"
b.
FREQUENCY
SCALE
to
"5oooHz"
1008.2 -12.66
Check the signal
on
the socket
"30kHz
and
35kHz"
(pin 4).
The
frequency should
be
35kHz.
If necessary adjust the iron core
"C"
in Z 2.
The
voltage should
be
approx.
2.7
V.
The
frequency should change to
30kHz.
If
not,
adjust the
air
trimmer "D" in Z 2 and
check
item a
again
.
Check
that
the frequency
at
the
"Output"
socket
is
10Hz
!o,5%.
If
not,
check
item
2.1.
b.
and
2.2.
Turn
FREQUENCY RANGE
to
0-5000
Hz.
Check the frequency
on
the
"Output"
socket:
5Hz
:!:o,5%,
If
necessary adjust C
133.
Check
that
the frequency on the
"Output"
socket (pin 1)
is
5 Hz.
If
not,
adjust the FREQUENCY
SCALE
ADJUSTMENT. Fine adjustment by a
knob and coarse adjustment by a screwdriver operated
capacitor.
In
case
that
the regulation range is tao far away
set
both
variable
trimmers in
mid position and adjust the
air
trimmer "8" in Z 2
for
5
Hz.
Check
that
the frequency
is
5ooo
Hz
.
If
not,
adjust
the
iron
core
"E" in Z 2 and
check
item a
again.