Philips PM 5101 - Amplitude; Distortion of the Sinewave Voltage; Electrical Check

17
- Set potentiometer R 18 to the centre position.
-
Tum the spindle of double potentiometer RI until the nominal fre-
quency
is obtained.
- Set the frequency dial to position
15 and tighten the nut without moving
the spindle
of double potentiometer RI.
- Check the frequency di al setting at 1500 Hz .
2. Electrical check
- Set the frequency dial to position 100.
- Set SK3 to position ""'.
- Set SK2
to position x 100.
- Check that the frequency is 10 kHz ± 2% (with the beat frequency
method).
- Set the frequency dial to position
10 .
- Check
that the frequency is 1kHz ± 2%. If necessary, adjust R18 so
that the frequency inaccuracy is smaller than 2%.
- Set SK2 to position x l
k.
- Set the frequency dia1 to position 10.
- Check that the frequency is 10 kHz ± 2%. If necessary, correct the
frequency with C22.
- Set the frequency dial to position
100.
- Check
that the frequency is 100 kHz ± 2%. If necessary, correct the
frequency with C1.
- Check the frequency
at all ranges in the positions 10 , 25, 40, 70 and
100
of the frequency dia!. Tolerance: ± 3% ± 0.7 Hz.
C. DISTORTION OF THE SINEWAVE VOLTAGE
- Set SK3 to position ""'.
-
Mea sure the distortion with a non-linear distortion meter.
The distortion should be smaller than 0.7% at 20 Hz and 100 KHz.
At l kHz the distortion should be smaller than 0.3%.
D. AMPLITUDE
- Set attenuator R2 to position 2.0 V.
- Set SK3 to position ""'.
- Check that the
output amplitud e (no 10ad at BU 1-BU2) at all fre-
quencies
is 2 V rms. If necessary, correct with R26.
- Set SK3 to position
'U .