Tektronix 3B5, Instruction Manual

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Operating Instructions— Type 3B5
Fig. 2-7. Circuit to provide single sweep and external horizontal input for the Type 3B5.
probe through the associated automatic/programmable
amplifier unit or remote seek through the front-panel PRO­
GRAM connector or the program connector of the associated
automatic/programmable amplifier unit. When the front­
panel SEEK button is pressed or a seek command is applied
to the front-panel PROGRAM connector, only the Type 3B5
seek circuits operate. When the seek command is received
through the associated automatic/programmable amplifier
unit, both units seek but the Type 3B5 seek circuits operate
after the amplifier unit has completed its cycle. The Type
3B5 does not seek
when
the seek button on the amplifier
unit is pressed.
When the Type 3B5 receives a seek command, the seek
circuits first seek a trigger signal in the mode selected by
the Trigger Function switch. If a trigger signal is present,
the seek circuits then seek a sweep rate which displays
between two and six cycles of the trigger signal (with nom ­
inal CYCLES/SWEEP adjustment). (Full description of the
electrical operation of the seek circuits is given in the Cir­
cuit Description section.) If a trigger signal is not present
(or the LEVEL control is incorrectly set), the seek circuits
switch to auto triggering and again check for a trigger
signal. If a trigger signal is present in the auto trigger
mode, the seek circuits seek a sweep rate which produces
2-12