BRUEL & KJAER 1024 - Distortion Measurement; Noise and Hum Measurement; Output Transformer Check

2.5 . Distortion
- a. ATTENUATOR: "12000 mV"
MATCHING IMP .: "Alt ."
COMPRESSOR S PEED: " Comp . Ofr'
SWITCH 07: "Scanning Ofr'
BANDWIDTH SE LECTOR : "Sine"
METER SWITC H: "0.3 sec. Output Volt. II
b. MATCHING IMP. to "60"
2.6 . Noise - Hum
MATCHING IMP .: "600"
COMPRESSOR SPE ED: "Comp. OFr'
SWITCH 07 : "Scanning Off"
BANDWIDTH SELEC T OR: "Sine"
METER SWITCH: "0.3 sec. Output Vo lt."
FREQUENCY SCA LE: "1000 Hz"
b. MATCHING IMP. to " 6000"
BANDWIDTH SEL ECTO R to "10 Hz"
2.7. Output Transformer
MATCHING IMP .: "600"
COMPRESSOR SPEED: "Comp. Ofr '
SWITCH 07: "Scanning Off"
BANDWIDTH SELE CTO R: "Sine"
METER SWITCH: "0.3 sec. Output Volt."
FREQUENCY SCALE: "1000 Hz"
1024 .2 - 1 _6 5
Adjust the OUTPUT LEVEL f", a 10 V deflection on type 2107 (10 V range)
and check the distortion of frequencies from 20 - 20000 Hz.
Distortion down to 0 .5% can be measured with type 2107 . lower distortion
requires use
of 1607 filter for rejection of fundamental frequency.
If 16lJ7 is available, check limi ts.
FREQUENCY SCALE:
max. distortion:
20
0.7
200
0.25
2000
0.25
20000 Hz
0.7 %
Connect a resistor of 6 Q to LOAD terminals and adjust OUTPUT LE VEl for 0
2 . 5 V defle ction on type 1024.
FREQUENCY SCA LE :
ma x. distortion:
20
1.2
200
0.5
2000
0.5
20000 Hz
1.2 %
The i nstru ment must be placed in its case or in other way effectively screened .
Adju st the O UTPUT LE V EL f", 0 1 0 V deflection on type 2107 (10 V range).
Depress GENERATOR S TOP and measure the noise and hum at line frequency
and
2n d and Jr d harmonic.
Nois
e:
Hum :
min.
65 dB below 1 0V
min. 70 dB below 10 V
Ch eck and tolerances as under item a.
Adju st the OUTPUT LEVEL for a 10 V deflection on type 1024.
Check all · other positio ns of MATCHING IMP . Deflection on type 1024
9.8 - 10 .2 V.