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DESCRIPTIONS
3 - 7
3.2.3
Triggering and time bases.
The sections for Main Time Base (MTB) and Delayed Time Base (DTB) are for the greater part
identical. Therefore the MTB part is extensively described and then the DTB part briefly.
Main Time Base Description.
The possible trigger sources are applied to the block MTB TRIGGER F AMPLIFIER. The
selection for triggering on the vertical channels 1,2, 3 or 4 is done in the Y-FUNCTIONS blocks in
the vertical section. Triggering is also possible on the LINE trigger signal that is derived from the
mains. The MTB TRIGGER F AMPLIFIER incorporates filters for HF- reject, LF-reject and
ac or dc signal coupling. The block also incorporates the +/- slope selection. The dc control signal
LEVEL MTB originating from the CONTROL CIRCUITS is routed via the PEAK-PEAK DETECTOR.
This block limits in peak-peak mode the LEVEL MTB range just within the peak-peak value of the
signal. For this purpose the trigger signal is applied to an input of the detector. The LEVEL MTB
control signal is not limited if the peak-peak mode is inactive.
For triggering on TV synchronization pulses the blocks TV CLAMP CIRCUIT and TV SYNC
SEPARATOR are used. The CLAMP CIRCUIT separates the synchronization pulses from the
composite video signal. The video information is not necessary for triggering. The TV SYNC
SEPARATOR filters out line, frame and field pulses. This is done for various TV systems including
HDTV.
The block MTB TRIGGER F AMPLIFIER sends trigger pulses to the MTB LOGIC. This logic
is combined with the DTB LOGIC. The three output signals are used to start MTB (applied to MTB
TIMING CONTROL), to switch intensity on and off (applied to Z CONTROL) and for ALTemate display
switching (applied to DISPLAY MODE + TRIGGER SOURCE CONTROL).
The MTB is based on the principle that selectable capacitors (inside block MTB TIMING) are charged
with a selectable constant current (from MTB CURRENT SOURCE). This results in a sawtooth
voltage across the capacitor(s) that rises linearly with the time. As a consequence a time-linear
horizontal deflection is obtained. The sawtooth voltage is routed to the horizontal deflection part via
the MTB SAWTOOTH PICK OFF. This block serves as a high to low impedance converter so that the
load to the timing capacitor(s) is minimal. Various time base sweep speeds are obtained by selecting
different combinations of current values and timing capacitors. The function MTB VARiable works via
the MTB CURRENT SOURCE.
The MTB TIMING CONTROL discharges the capacitor(s) if the maximum level of the sawtooth is
reached. The MTB TIMING CONTROL allows the charging process to start again if a trigger occurs.
The functions X POSition, HOLD OFF and 10x MAGN are applied to and realized in the MTB TIMING
CONTROL. HOLD OFF determines the time between discharge of the timing capacitors and the
moment that a trigger pulse is allowed to start the MTB again.
The MTB TIMING CONTROL accomplishes the DELAY time function. The sawtooth voltage is
compared with an adjustable dc voltage. The DTB is started where both voltages have the same
level: this condition is signalled to the DTB LOGIC via signal START.
The MTB TIMING CONTROL also plays a role in the automatic MTB calibration. A reference voltage
MTBCALREF is compared with the sawtooth voltage. The time necessary for the sawtooth to reach
the MTBCALREF level is monitored by the microprocessor via signal MTBCAL. If necessary the MTB
is readjusted. Automatic calibration oftheX-path (including output circuit of MTB TIMING CONTROL)
is done with accurate voltages from the block X DEFLECTION CALIBRATION.
Delayed Time Base Description.
The function of DTB TRIGGER F AMPLIFIER is identical to the corresponding block in the
MTB part. A "peak-peak detector" for LEVEL DTB is not present. The range of this control is always
fixed and not related to the peak-peak level of the signal. Blocks for TV triggering are not present in
the DTB section. TV triggering of the DTB occurs via output signals from the TV SYNC SEPARATOR
in the MTB section.
Summary of Contents for PM3082
Page 34: ...DESCRIPTIONS 3 1 ST8235A 970415 ...
Page 35: ...DESCRIPTIONS r _A1 SIGNAL UNIT TRIGGERING ...
Page 36: ...3 1 TIME BASES ST8235A 970415 ...
Page 37: ...3 2 DESCRIPTIONS ST82358 97041S ...
Page 38: ...XYSW ...
Page 79: ...5 1 22 UNIT DESCRIPTIONS Lay out 2 Small component side of signal unit A1 ...
Page 93: ...5 1 33 09001 2 01201 3 01201 5 C 1 O 6 0 T 10n A1 Diagram 1 Attenuator CH 1 PM3094 PM3092 ...
Page 96: ...5 1 34 UNIT DESCRIPTIONS 09001 17 A1 Diagram 2 Attenuator CH 2 PM3094 PM3092 ...
Page 99: ...5 1 35 X I STB241 970420 A1 Diagram 2a Attenuator CH 1 PM3094 PM3092 ...
Page 100: ...5 1 36 UNIT DESCRIPTIONS 12AT3 12AT3 STQ24S 970420 Diagram 3 Attenuator CH 3 PM3094 ...
Page 101: ...J a C3077 I I T b M A AT350C N1101 2AT3 12AT3 ...
Page 102: ...5 1 36 UNIT DESCRIPTIONS 12AT3 STB242 970420 Diagram 3 Attenuator CH 3 PM3094 ...
Page 104: ...5 1 37 12AT4 D4201 3 D4201 5 ST8243 97D420 Diagram 4 Attenuator CH 4 PM3094 ...
Page 105: ...UNIT DESCRIPTIONS C4071 lOn C4072 lOn AC DC f HIGH IMPEDANCE ATTENUATOR LF IMPE CONVE R40Q2 ...
Page 107: ... 12AT 12AT4 l i C4067 160u 25V C4068 10n K4002 ...
Page 109: ...I i 04097 1 0 O u 25V J 25V 10n 25V ...
Page 113: ...UNIT DESCRIPTIONS PROBE CALIBRATOR GNOR6F f 1CVREF f C11S0 180u 25V C1157 10 0n GNDREF GNDREF ...
Page 115: ...5 1 40 UNIT DESCRIPTIONS Diagram 6 Preamplifier CH 1 and CH 2 ...
Page 116: ...PAOREF N32Q2 12 ...
Page 117: ...5 1 40 UNIT DESCRIPTIONS Diagram 6 Preamplifier CH 1 and CH 2 ...
Page 118: ...UNIT DESCRIPTIONS 5 1 41 l GAIN CONTROLVAR X1 2 X5 Diagram 7 Preamplifier CH 3 and CH 4 ...
Page 119: ...UNIT DESCRIPTIONS ...
Page 120: ...5 1 41 PMVAR ft4220 Diagram 7 Preamplifier CH 3 and CH 4 ...
Page 121: ...5 1 42 UNIT DESCRIPTIONS Diagram 8 Y functions ...
Page 122: ... 12FNC12 I2R4C12 12FNC34 12FNC34 R1S13 1K47 FNC FI ...
Page 123: ...5 1 42 UNIT DESCRIPTIONS 12FNC12 FM2MV 00003 7 12FNC12 H2FNC12 Diagram 8 Y functions ...
Page 124: ...UNIT DESCRIPTIONS 10P 120LD REF VOLTAGE DG001 HEF40M I f 1 ...
Page 129: ... REF VOLTAGE j D5001 HEF4009 DS001 HEF40M If C0RHECT10N VOLT N5001 366 f ...
Page 133: ...5 1 45 D5501 HEF4053 CNT STB251 970428 Diagram 10 Display and trigger control ...
Page 138: ...5 1 47 Diagram 12 MTB trigger ...
Page 142: ...5 1 48 UNIT DESCRIPTIONS TV SYNC SEPABATOtT TV UNE FRAME SEUECTKDN Diagram 13 TV line trigger ...
Page 143: ...UNIT DESCRIPTIONS 5 1 49 160TR Diagram 14 DTB trigger ...
Page 146: ...5 1 50 UNIT DESCRIPTIONS Diagram 15 Time base logic ...
Page 148: ...5 1 50 UNIT DESCRIPTIONS V 6 0 0 4 Diagram 15 Time base logic ...
Page 149: ...UNIT DESCRIPTIONS 5 1 51 Diagram 16 Main time base ...
Page 150: ...UNIT DESCRIPTIONS R6001 ...
Page 151: ...5 1 51 ...
Page 153: ......
Page 154: ...5 1 52 UNIT DESCRIPTIONS R716Y C7181 ONLY IN PM30Q2 PM3004 Diagram 17 Delayed time base ...
Page 155: ...UNIT DESCRIPTIONS 5 1 53 X9001 I 1 D 0 O O 8 1 Diagram 18 Connectors ...
Page 214: ...UNIT DESCRIPTIONS 5 2 13 5 2 5 Circuit diagrams A2 200 MHz version ...
Page 215: ...UNIT DESCRIPTIONS 5 2 5 Circuit diagrams A2 200 MHz version 0501 22 ...
Page 216: ...5 2 13 ...
Page 217: ...5 2 14 UNIT DESCRIPTIONS A2 200 MHz Diagram 2 Final Y output stage ...
Page 218: ......
Page 219: ...5 2 14 UNIT DESCRIPTIONS STB263 970428 A2 200 MHz Diagram 2 Final Y output stage ...
Page 223: ...5 2 16 UNIT DESCRIPTIONS AC20mV DC 10V AC 80mV OCMOV A2 200 MHz Diagram 4 Final Z amplifier ...
Page 224: ...AC 60mV DC 1CV R3311 511E M20Q2 11 AST03 R3313 1 2KB7 V3311 ...
Page 226: ...UNIT DESCRIPTIONS 5 2 17 A2 200 MHz Diagram 5 Modulator demodulator and focus control ...
Page 227: ...UNIT DESCRIPTIONS FOCUS L i X2401 ...
Page 228: ...5 2 17 A2 200 MHz Diagram 5 Modulator demodulator and focus control ...
Page 231: ...8 5 ii 8 HI I Hl H s HI I i HI I ...
Page 232: ...g I S 5 S I 1 H H r lr H J g if j r r 8 3 8 8 S 3 5 5 H H 5 3 r l r l H H n ft 3 S 5 8 a s 5 ...
Page 268: ...UNIT DESCRIPTIONS 5 2 11 Circuit diagrams A2 100 MHz version ...
Page 269: ...5 2 47 ...
Page 270: ...5 2 48 UNIT DESCRIPTIONS TO CflT ...
Page 271: ......
Page 280: ...UNIT DESCRIPTIONS X2411 ...
Page 281: ...5 2 51 FOCUS LEVELSHIFTER A2 100 MHz Diagram 5a Modulator demodulator and focus control ...
Page 284: ... ...
Page 285: ...a 5 a I H rI 3 H H H 8 K fc 5 3 3 I I ...
Page 308: ...t 0 0 0 0 0 0 0 0 0 3 sS cn 03 03 UNIT DESCRIPTIONS ...
Page 310: ...R1102 R1101 R1679 R1672 R1071 R1104 B1674 u HI 406 H i402 D1402 O N j oo O O ai 5 3 ...
Page 311: ...bc646c Up BC866C 3Lp ...
Page 313: ......
Page 317: ...UNIT DESCRIPTIONS 5 3 9 5 3 5 Circuit diagrams Diagram 1 Central processor unit ...
Page 318: ...UNIT DESCRIPTIONS 5 3 5 Circuit diagrams ...
Page 319: ...5 3 9 r i Diagram 1 Central processor unit ...
Page 324: ...UNIT DESCRIPTIONS ...
Page 325: ...5 3 11 Cl 968 T 1 0 0 n C1963 I80u Diagram 3 Potentiometer DAC and lEEE option h i m ...
Page 326: ...5 3 12 UNIT DESCRIPTIONS G4 oi TEXT CURSOR CONTBOL 12MG Diagram 4 Text and cursor circuit i ...
Page 328: ...5 3 12 UNIT DESCRIPTIONS G4401 12MG TEXT CURSOR CONTROL Diagram 4 Text and cursor circuit ...
Page 342: ...UNIT DESCRIPTIONS 5 4 4 Unit lay outs TO X5201 ON CRT CONTROL A5 I O C O I D C G C I ...
Page 344: ...UNIT DESCRIPTIONS 5 4 4 Unit lay outs TO X5201 ON CRT CONTROL A5 H cc c c IH ...
Page 360: ...sna iu o UNIT DESCRIPTIONS 5 5 3 5 5 3 Circiuit diagram X5201 A5 Diagraml CRT controls unit ...
Page 367: ...UNIT DESCRIPTIONS 5 6 3 Unit lay outs TO X2401 ON ...
Page 369: ......
Page 371: ......
Page 372: ... 00 o o O o ...
Page 377: ...UNIT DESCRIPTIONS 5 6 5 Circuit diagrams G LI 001 fKfcjH ...
Page 379: ...5 6 10 t ...
Page 381: ... EHT CONVERT ...
Page 383: ...UNIT DESCRIPTIONS OUTPUTCIRCUIT V1271 BYV29 T1001 T1001 T1001 now T1001 T1001 now now ...
Page 394: ...UNIT DESCRIPTIONS 5 7 1 5 7 RESERVED FOR FUTURE EXTENSIONS ...
Page 395: ...UNIT DESCRIPTIONS 5 8 1 5 8 RESERVED FOR FUTURE EXTENSIONS ...
Page 396: ...UNIT DESCRIPTIONS 5 9 1 5 9 RESERVED FOR FUTURE EXTENSIONS ...
Page 397: ...UNIT DESCRIPTIONS 5 10 CONNECTOR BOARD A10 5 10 1 Unit lay out ...
Page 399: ...UNIT DESCRIPTIONS 5 10 CONNECTOR BOARD A10 5 10 1 Unit lay out 28 27 O O X IAJ 2 1 ...
Page 412: ...UNIT DESCRIPTIONS 5 11 3 Fig 1 Location of options Y out and external trigger ...
Page 413: ...UNIT DESCRIPTIONS ...
Page 414: ...5 11 3 Fig 1 Location of options Y out and external trigger ...
Page 415: ...5 11 4 UNIT DESCRIPTIONS Fig 2 Printed circuit board lay out of Y out unit ...
Page 417: ...UNIT DESCRIPTIONS 12V 12V 12V 12V X1003 YOP HX R1001 I 1 2 K 1 X1009 X1010 SCL ...