![Tektronix 2236 Instruction Manual Download Page 48](http://html.mh-extra.com/html/tektronix/2236/2236_instruction-manual_1078848048.webp)
Theory of Operation— 2236 Service
DETAILED CIRCUIT DESCRIPTION
The detailed circuit description contains two parts. The first part describes the conventional oscilloscope operation and the
second contains the operation of the counter-timer-multimeter circuitry.
OSCILLOSCOPE
The oscilloscope part of the 2236 Oscilloscope functions as a conventional oscilloscope. In addition, signals are produced
by the circuitry for use by the CTM when making front-panel voltage and timing measurements.
VERTICAL ATTENUATORS
The Channel 1 and Channel 2 Attenuator circuits, shown
on Diagram 1, are identical with the exception of the addi
tional Invert circuitry in the Channel 2 Paraphase Amplifier.
Therefore, only the Channel 1 Attenuator will be described
and the Invert circuitry of Channel 2 will be discussed
separately.
The Attenuator circuit (see Figure 3-1) provides control of
input coupling, vertical deflection factor, and variable volts-
per-division gain. Input signals for crt vertical deflection may
be connected to the CH 1 OR X and the CH 2 OR Y input
connectors. In the X-Y Mode of operation, the signal applied
to the CH 1 OR X connector provides horizontal (X-Axis)
deflection for the display, and the signal applied to the CH 2
OR Y connector provides the vertical (Y-Axis) deflection for
the display.
Input Coupling
The signal applied to the CH 1 OR X input connector can
be ac coupled, dc coupled, or disconnected from the input of
the High-Impedance Input Attenuator circuit. Signals applied
to the CH 1 OR X input connector are routed through resis
tor R9100 to Input Coupling switch S I. When S I is set for
dc coupling, the Channel 1 signal is applied directly to the
input of the High-Impedance Attenuator stage. When ac
coupled, the input signal passes through dc-blocking capac
itor C2. The blocking capacitor prevents the dc component
of the input signal from being applied to the Attenuator cir
cuit. When switched into the signal path, attenuators ATI
and AT2 attenuate the input signal by factors of 100 and 10
respectively. When S I is set to GND, the direct signal path
is opened and the input of the Buffer Amplifier is connected
to ground. This provides a ground reference without the
need to disconnect the applied signal from the input connec
tor. The coupling capacitor precharges through R4 to pre
vent large trace shifts when switching from GND to AC.
3-4
Figure 3-1. Block diagram of the Vertical Attenuators.
Summary of Contents for 2236
Page 10: ...2236 Service viii The 2236 Oscilloscope ...
Page 74: ...Theory of Operation 2236 Service 3 30 ...
Page 102: ...Performance Check Procedure 2236 Service 4 21 Figure 4 1 Test setup for DMM common mode check ...
Page 242: ...2236 Service 4204 34 Figure 9 6 CTM basic block diagram ...
Page 243: ...DMM POWER S U P P LIE S 2236 Service F ig u re 9 7 C T M d e ta ile d b lo c k diag ram ...
Page 254: ...S I 0 O I 5 1 S O i 4204 21 C IR C U IT BOARD INTERCONNECTIONS ...
Page 267: ...1 2 3 4 5 6 7 8 9 J T K L M_ _ ___ N___l _ P____l S ...
Page 271: ...1 2 3 4 5 6 7 8 9 lO P2SO O U1 A TRIGGER V T O W2500 5 A 223 R E V A P R W G ...
Page 275: ......
Page 280: ......
Page 285: ...A 6 F IL T E R B O A R D lo c a te d u n d e r H V S h ie ld ...
Page 313: ...2236 Service T O U I 3 0 0 4 8 K T O UI300 II S K 0 2 2 3 6 Z Z O A Z 2 OPTION IA ...
Page 317: ...A 10 C O U N T E R T IM E R M U L T IM E T E R B O A R D A D J U S T M E N T LO C A T IO N S ...
Page 319: ...2236 Service TROUBLESHOOTING GUIDE 4206 99 4204 69A ...
Page 323: ...9 ...
Page 324: ...2 REV APR 1986 ...
Page 325: ...2236 SERVICE ...
Page 326: ......
Page 332: ......
Page 333: ...2236 SERVICE ...
Page 334: ...2 4 2 1 ...
Page 338: ......