Philips PM 5125 Manual page 32

- The square wave voltage between terminals BU4 and BU7 (un-
loaded) should be between 10.0 VpP and 10.5 VPo. The rise and the
fall time should be less than 120 nanoseconds.
Measure this voltage by means of an oscilloscope.
2. -Check that the square wave is clean for all settings of switch SK3
and of the frequency dial. The sag and the overshoot of the square
wave should be less than 2%.
3. - Connect a load of 600 H to terminals BU 1 and BU2 and repeat the
check indicated in point 2.
H. METER CIRCUIT
1. -Set switch SK2 to position ~,.
- Set switch SK3 to position x 102.
- Set switch SK4 to position 0 dB.
- Set the frequency dial to position 50.
- Adjust attenuator R2 so that the output voltage between terminals
BU4 and BU7 is 10 VPP.
- Adjust the meter reading to ]0 V f 1% by means of RI05.
2. -Set switch SK2 to position ~.
- Adjust attenuator R2 so that the output voltage between terminals
BU4 and BU7 is 10 Vr~s.
- Adjust the meter reading to 10 V ~ 50 mV by means of RI01.
3. -Adjust the output voltage between BU4 and BU7 successively to
8 V, 6 V, 4 V and 2 V by means of attenuator R2. Note the cor-
responding readings of meter Ml.
The difference between the meter readings and the output voltage
should be less than 200 mV.
4. -Check that the meter readings at 10 Hz and 1 MHz do not differ
more than 2 % from the corresponding output voltage measured
at the terminals BU4-BU7.
I. SYNCHRONISATION
- Apply a signal of 100 mVrme f 5% - 5 kHz to the terminals BU3 and
BUS.
- Set switch SK3 to position x 102.
- Set switch SK2 to position ~.
- Set switch SK4 to position 0 dB.