BRUEL & KJAER 2203 - p005

Overload
Att. black: "1 20 dB"
Att. transp.: "120dB"
Meter Switch: "Lin.-Fast"
Frequency Response
Att. black: "1 20 dB"
Att. transp. : "1 20 dB"
Meter Switch: "Lin.-Fast"
Meter Switch through A , B and C positions
Overshoot
Noise
Att. black: "1 20 dB"
Att . transp.: "1 20 dB"
Meter Switch: "Lin.-Fast"
Meter Switch to " Lin. - Siow"
Att. black : "70 dB"
Att. transp.: " 10dB"
Meter Switch: "A-Fast"
Att. transp. to "30 dB"
Meter Switch to: "Lin.-Fast"
Att . transp. to "fully CCW position"
Meter Switch to " Ext. Filter-Fast"
Att. balck to "1 30 dB"
Att. transp. to " fully CCW position "
Meter Switch to " Lin. - Fast"
9.73
Checking and Adjusting 2203.1
Apply a signal of 3.45 V RMS to the input of 2203 through adaptor JJ 2614, and turn
"Adj." to produce 3,16 Von "Output".
Increase the input signal by 1 0 dB and check that the voltage on "Output" follows the 1 0 dB
increase.
This test ensures that the working voltages are correct in the different amplifier stages.
Adjust an input signal at 1 kHz to produce an 8 dB deflection on the meter.
At 10Hz P 201 on ZE 0117 should be adjusted for a deflection of 9,5 dB± 0,25 dB.
At 25kHz the deflection should be between 7 and 8 dB, and at 40kHz between 6,5 and
7,5 dB. (C 408 on ZE 0118 can be changed between 2,7 pF and 12 pF).
Change frequency to 1 kHz and check the deflection to be 8 dB.
The
deflection should remain at 8 dB in all positions .
If necessary adjust: P 202 in position A
P
203 in position B
P
204 in position C
onZE0117
The Overshoot when connecting a 2kHz input signal should be checked with reference to a
constant signal producing a deflection of 6 dB as well as - 5 dB.
Overshoot: 0,1 - 1,1 dB (damping resistor is R 701 across the meter)
Overshoot: 0,1 - 1,6 dB (damping network R 418 and C 413 on ZE 0118)
The instrument must be in its case, " Adj. " turned to a K-factor reading of OdB , and the input
should be terminated with a capacity of approx. 50 pF . The best way to arrange this is to
shortconnect the input of a JJ 261 5 Adaptor , which has already a 50 pF Glass-capacitor
built in. If this Adaptor is not available , a 50 pF capacitor can be mounted inside a B & K Plug
JP 01 01 which is then connected to the input via JJ 261 4, but this methode is more critical
as regards moisture on contacts etc .
Max . noise deflection 4 dB on the meter .
Max. noise deflection 3 dB on the meter .
If the noise exceeds these limits , proceed as follows :
If
a Frequency Analyzer is available, it should be checked whether the noise is caused by the
DC Converter . This is done by measuring selectively around 1, 2 and 3kHz on "Output".
(max . 50 mV).
If the deflection exceeds - 10dB on the meter , the Output Amplifier ZE 0118 seems to be
causing the noise .
If the deflection is below - 1 0 dB, proceed as follows :
If
the deflection now exceeds full scale the source of noise is somewhere in the Input Ampli-
fier ZE 0117 (Probably V 201 to 204) .
If
the deflection is less than full scale the source of noise is found in the Impedance Conver-
ter ZE 0116 (Probably V 101 or 1 02) .
Valid from serial no. 4671 52
1-3