Output Circuit And Dc Offset - Philips PM 5775 Manual

59
C. OUTPUT CIRCUIT AND DC OFFSET
C1.
Preliminary settings of controls:
PM 5775-( PM 5776)
REPETITION TIME, S1 10 us
FINE, RV1 12 o'clock
DELAY, S82 100 ns
FINE, RV2 fully counter-clockwise
WIDTH, 83 1 us
FINE, RV3 fully counter-clockwise
CONT. GATED, S6 CONT
SINGLE DOUBLE, $7 SINGLE
AMPLITUDE IN 50 Q, S4 —3V
Vernier, RVS MAX.
DC OFFSET IN 50 Q, RV4 OV
NORM. INV., S8 INV.
PM 3400
mV/cm 50, CAL
TIME/cm 2 ps
Connect socket PULSE OUT 50 Q, P3, to one of the oscilloscope inputs via a 50 Q
coaxial cable and a 20 dB attenuator (e.g. General Radio GR874 G20). Connect
socket SYNC. OUT, P2, to the TRIGG. input of the oscilloscope via a 50 Q
coaxial cable and a 20 dB attenuator (e.g. Texscan type FP 50, BNC Outline A).
Bias Z330
— Observe a flat pulse top on the oscilloscope screen. If required, adjust with
RV301. Fig. X-4 shows unacceptable deviation.
correct shape set with RV302
a
Q.=ta=
unacceptable deviation
-3V- MAE&499
Fig. X-4. Pulse diagram