BRUEL & KJAER 2804 Operating instructions

BROEL & KJ.ER
Ne2rum - Denmark
Consisting of:
How
to Open the Metal Case
Service Instructions
Microphone PolNer Supply
Electronic Section
Position of Components
Parts
list
Circuit Diagram
2804.1
2804.2
2804.3
2804.4
2804
Tum the thumb screw on the front plate anti-clockwise. The bottom plate can then be slid backwards and removed.
Unscrew the
two 3 mm screws on the back plate. The two side plates can then be slid backwards and removed.
Battery Change
Unscrew the upper 3
mm screw on the back plate and slid the top plate backwards. The batteries can then easily be changed.
Trouble Shooting
If any problems should occur with this instrument, then first check the DC working voltages from the Power Supply. Then use the
Block Diagram in order to localize the trouble to be located in one specific circuit.
When a fault has
been found and corrected, the voltages and adjustment which are influenzed by the correction must be rechecked,
and
the instrument controlled to see if all basic functions are fulfilled.
The tolerances stated in the instructionscan only be used as a guide for adjustment and control.
Any deviations must not be corrected without being sure, that the tolerances, of the instruments used for making the adjustment, are
so small as
to have no influence on the measurements.
The instructions in this Manual are given purely as a guide to the service of the equipment . Some faults, as for example, small
deviations in tolerances require for their corrections special control equipment and extensive experience,and in these cases it is
necessary to send the instrument to the factory.
Voltages at various points throughout the apparatus are indicated on the circuit diagram and the simplified diagram in the service
instructions. These voltages are typical nominals only and with
the exception of stabilized power supply voltages, may vary
considerably from apparatus to apparatus.
Spare Parts
Please state serial number of apparatus when spare parts are ordered.
2804 · 9.79

BROEL & KJ.ER
Ncerum -Denmark
Consisting of :
How
to Open the Metal Case
Service Instructions
Microphone Povver Supply
Electronic Section 2804 .1
Position of Components 2804 .2
Parts List 2804 .3
Circuit Diagram 2804 .4
2804
Turn the thumb screw on the front plate anti-clockwise . The bottom plate can then be slid backwards and removed.
Unscrew
the two 3 mm screws on the back plate . The two side plates can then be slid backwards and removed.
Battery Change
Unscrew
the upper 3 mm screw on the back plate and slid the top plate backwards . The batteries can then easily be changed.
Trouble Shooting
If any problems should occur with this instrument, then first check the DC working voltages from the Power Supply . Then use the
Block Diagram in order to localize the trouble to be located in one specific circuit .
When a fault has been
found and correc ted , the voltages and adjustment which are influenzed by the correction must be rechecked,
and the instrument controlled to see if all basic functions are fulfilled.
The tolerances stated in the instruct ions can only be used as a guide for adjustment and control.
Any deviations must not be corrected without being sure, that th e tolerances, of the instruments used for making the adjustment, are
so small as to have no influence on the measurements .
The instructions
in this Manual are given purely as a guide to the service of the equipment . Some faults, as for example, small
deviations in tolerances require for their corrections special control equipment and extensive experience, and in these cases it is
necessary to send the instrument to the factory .
Voltages at various points throughout t he apparatus are indicated on the circuit diagram and the simplified diagram in the service
instructions. These voltages
are typical nominals only and with the exception of stabilized power supply voltages, may vary
considerably from
apparatus to apparatus .
Spare Parts
Please state serial number of apparatus when spare parts are ordered.
Instruments and accessories necessary for repair
Multi meter (50 pA)
DC Power Supply
Electronic DC Voltmeter (Ri > 10 Mn )
Microphone Amplifier 2606
Filter Set 1614
Microphone Preamolifier 2619
Input Adaptor JJ 2615
Screened Plug JP 0101
2804-12 . 69

•
•
•

BROEL & KJ..ER
Ncsrum -Denmark
Simplified Diagram
170Y"-
_T_
Oscillatot" frequency: 40kHz
1.1 Battery Indicator
2804.1-1 . 73
Electronic Section 28041
Valid from serial no. 302246
P4
N 1
Pol.
P3
211V
P2
lnt ln2
Supply a voltage of 3.5 V ± 0.1 V to the terminals of the battery compartment .
The meter should now deflect to a point ~ red and green part of the scale.
If necessary adjust Pl .
continued

1.2 Power Consumption
1.3
Stability of Output Voltage
~ .. -------
-·
1.4 Polarization Voltage
N1 in position 28 V
N1 in position 200 V.
1.5 Noise and Hum
2804.1 . 9.79
Supply a voltage of 4 V ± 0.1 V to the terminals of the battery compartment, and
adjust the consumption to 60 mA by means of P2 .
a. Supply a voltage of 5 V to the terminals of the battery co mpartment.
Check the voltage on - .. 2S V DC Outlets': 28 V t9.!_erance ± 10 %.
b. Change the supply voltage to 3.5 V and load the "28 V DC Outlets" with a 7 kn
resistor.
-· ~ ).--··~' ·--~-'
Check the output voltage: 28 V to~ ' rance : ± 10% -=..:: ,:
Measuring Amplifier 7
(f . ins1 2609 l
a. Measure the polarization voltage with a high impedance DC voltmeter.
Polarization voltage: 28 V
±0 . 1%
If necessary adjust P3 . (Check that the supply voltage is 4 V)
b. Check the POL. VOLT . on Measuring Amplifier (f . inst. 2609) and if necessary
adjust for 200 V exactly.
Connect a DC meter between POL.
VOLT . sockets on type 2804 and 2609,
and adjust P4 for OV deflection on the DC meter (1 · 3V range).
Remember ground connection between the two instruments.
_r-=- cc:::=:H 2615:::r:::=261:::>-9 -~1-----+-'411..__: _CZJ_/ ------.J.I
2804 Freq . Analyzer
Measure the voltage on "Out
1" :max 30~JV (lin 20Hz · 20kHz)
max 70~JV (selective 1/3 oct~ve band from
20Hz · 80kHz)

BROEL & KJA:R
Ncerum - Denmark
Simplified Diagram
170V'\.
_T_
Oscillator frequency: 40kHz
1.1 Battery Indicator
2804.
1-1.73
Electronic Section
Valid from serial no. 302246
P4
P3
N1
Fig .1
N 1
2804.1
Pol.
28V
ln1 ln2
Supply a voltage of 3.5 V ± 0.1 V to the terminals of the battery compartment.
The meter should now deflect
to a point between red and green part of the scale:
If necessary adjust P1 .
continued

1.2 Power Consumption
1.3 Stability of
Output Voltage
1.4 Polarization Voltage
N1 in position 28 V
N1 in po si tion 200 V.
1.5 Noise and Hum
2804 . 1-1 .73
Supply a voltage
of 4 V ± 0.1 V to the terminals of the battery compartment, and
adjust
the consumption to 60 rnA by means of P2 .
a. Supply a 1 oltage of 5 V
to the terminals of the battery compartment.
Check
the voltage on "28 V DC Outlets': 28 V tolerance ± 10 %.
b. Change the supply voltage to 3.5 V and load the "28 V DC Outlets" with a 7 kn
resistor.
Check
the output voltage: 28 V tolerance: ± 10 %.
a. Measure the polarization voltage with a high impedance DC voltmeter.
Polarization voltage: 28 V ±0.1%
If necessary adjust P3. (Check that the supply voltage is 4 V)
b. Check the POL. VOLT. on Microphone Amplifier type 2606 and if necessary
adjust for
200 V exactly.
2804
Connect a multi met er between POL. VOLT. sockets on type 2804 and 2606,
and adjust P4 for OV deflection on the mu ltimeter ( 1-3 V range)
Remember ground connection between the
two instruments.
External Filter
! ~'~
2606
1614
a. ·Switch
1614 to "Lin 22. 4- 22 400Hz "
Noise: max 30 fJV
b. Switch 1614 to "1/3 Octave" and measure the noise selectively in the
frequency range from 20 Hz to 80 kHz.
Noise: max
10 pV .
•
•
•
•

BROEL & KJA:R
Ncerum - Denmark
+Battery
2804.2-1.73
Position of Components
2804.2
valid from serial no. 408601
Meter
Pol. Voltage 28 V Heating
ZG 0031
Printed Circuit XC 1018
2 804

•
•
•
•

BROEL & KJ.ER
Ncerum - Denmark
CIRCUIT COMPONENT
DIAGRAM TYPE
REF.
CAPACITORS:
c 1 Polyester
C2
C3
C4
C5 Electrolytic
C6
C7,8
Tantalum
C9 Electrolytic
C10 Polyester
c 11 , 12 Tantalum
47nFI400 V
0. 1fJF I 250V
0.22f.JF/250 V
0.47tJF I100 V
2tJF I 64 V
22 fJFI100 V
56tJF I 6.4 V
640fJF I 6.4 V
10fJF I250 V
1.5 I'FI35 V
Parts-List
valid from serial no. 408601
STOCK
REF.
cs 0109
cs 0013
cs 0017
cs 0335
CE 0401
CE 0616
CF 0001
CE 0206
cs 0403
CF 0008
Cl RCUIT COMPONENT
DIAGRAM TYPE
REF.
TRANSISTORS:
V1
V2
V3
V4
Silicon
MISCELLANEOUS:
Feet
Handle
2804.3
NPN 2N3704
BC109
PNP 2N4289
NPN BC107
STOCK
REF.
VB 0028
VB 0047
VB 0049
VB 0032
COl
LS AND TRANSFORMERS:
Front Panel
Cover Panel
Rear Panel
Side Panel
Bottom Plate
Top Plate
OF 7015
DH 0052
FA 0405
FA 0406
F8 0304
GV 0673
GV 0914
GV 1108
L 1,2 Coil
L3
L4
DIODES:
01
02
03
04
Transformer
Silicon 8YX10
Zener 1N4004 MZ28
ZF9.1
POTENTIOMETERS:
p 1,2 Trimmer
P3
P4
RESISTORS:
R 1 Carbon 114 W
R 2 11
3W
R3
R4
R5
R6
R7
R8
R9
R10
R 11, 12
114 w
PRINTED CIRCUIT:
XC 1018
2804.3-1.73
LJ 0009
LJ 0008
L8 0679
1200VI 0.15 A OV 0025
400 VI 1 A
OV 0237
28.5VI 10 mA
OV 1120
8.5-9.6V I 30 rnA OV 1109
Carbon 100kn PG 4107
220 kn PG 4203
1Mn PG 5107
5% 330 n R8 2330
10%
100 n
150 n
2%
20 kU
10%
80 kU
2% 380 kn
780 kU
1.2 Mn
8M n
10%
10MU
5% 820 n
RB 2820
with components ZG 0031
M1
01
Moving Coil Instrument 40,uA
Miniature Socket, 28 V DC
Screened Socket, Output
7-pin socket, Input
Socket, Pol. Volt . Heating
Switch
Elements 1.5 V
Knob SN2022+
Battery Component
IM 0020
JJ 0031
JJ 0108
JJ 0705
JT 8344
OH 3001
OB 0004
YO 2003
YJ 0399

•
•
•
•

..,
~
:,.
L
~
BYX 10
1,2M.n.
13-03-1969 I 273565
B[)
c 0
E 0
2N 3704
~
: ',,
Transistor sockets
B
EOC
BC107
BC109
Bottom view
I ~ ' ~----------------r-----~
I
I
I
I
I
I
I
I
IQ1
I
'
',
70k.n
R 5
rn
E
c
B
2N 4289
10M.n
R10
Ii~,,,
Ol Pol.
ZOJ
li! "'
2 a
3m
·'
or2D
~ ~
3 .....
c ~
~"'
Q
Q'i .,
a: n
, c
3 ;:;
!. c
~ a;·
. (Q
.1>- .,
~ D)
~ 3
1\)
co
0
~
•
~
R ~ Microphone Power Supply
22-08-1972
3022'6
Bruel & Kjcsr
CopenhoQen
~. J I,_.,_,, I """ I I I ~ · Type 2804 I
BD 0080-11