Philips PM 5775 Manual page 31

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When the gate pulse is applied, the Schmitt-trigger Z203-Z204 switches over so
that the cathode level of Z212 becomes high, as long as the gate pulse is present.
At the same time, Z211 will be cut off because the base bias decreases and the
multivibrator starts oscillating. The output pulses of the multivibrator can then
affect the differential amplifier Z215-Z216 as long as the level on the cathode of
Z212 is high, so in this mode during the presence of the gate pulse.
A.4. Sync. output amplifier
Z215 and Z218 form a differential amplifier which is switched over by a positive
pulse at the base of Z215 to the state Z218 conducting and Z215 cut-off.
This differential amplifier is followed by a second balanced differential amplifier
consisting of Z217 and Z220. In the quiescent state Z217 is conducting and Z220
cut off. Z217 supplies output sync. pulses and because Z217 is conducting when
the differential amplifier is in the quiescent state, the level of the signal at socket
SYNC. OUT, P1, is almost 0 V. When the differential amplifier switches over Z217
is cut off and Z220 conducts via R237 and delay line DL201. The sync. output
pulse at socket SYNC. OUT will be 1.5 V into 50 Q.
A.5. Pulse delay circuit
The pulse delay circuit is controlled by a 4 ns pulse produced in the collector of
transistor Z224. Z223/Z224 forms a differential amplifier whose bases are
connected to the emitter resistors R233 and R236 of the emitter followers Z222
* and Z225 (Fig. VII-1).
+20V
to) jtotdns
pees
IF fo
to+4ns
——® CURRENT PATH IN THE REST POSITION
~———™ CURRENT PATH WHEN Z 224 CONDUCTS
MA $747
Fig. VII-1. Simplified diagram of the pulse delay trigger circuit