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Operating Instructions—455/A 2/B 2
2. Set the VER T MODE switch to either CHOP or A LT .
In general, CHOP is more suitable fo r low-frequency
signals and the A L T position is more suitable fo r high-
frequency signals. Position both traces to the graticule
horizontal centerline.
3. Set the triggering SOURCE switch to CH 1.
4. Connect the reference signal to the CH 1 inp ut connector
and the comparison signal to the CH 2 input connector. Use
coaxial cables or probes which have equal tim e delay to
connect the signals to the input connectors.
5. If the signals are of opposite polarity, set the IN VER T
switch in to invert the Channel 2 display. (Signals may be
o f opposite polarity due to 180° phase difference; if so,
take this into account in the final calculation.)
6. Set the CH 1 and CH 2 V O LT S /D IV switches and the
CH 1 and CH 2 V A R controls so the displays are equal and
about five divisions in amplitude.
7. Set the T IM E /D IV switch to a sweep rate which displays
about one cycle o f the reference waveform.
8. Turn the VAR T IM E /D IV control until one cycle of
the reference signal (Channel 1) occupies exactly eight
divisions between the first and ninth graticule lines (see
Fig. 2-7). Each division of the graticule represents 45° o f
the cycle (360° -r 8 divisions = 45°/division). The sweep
rate can be stated in terms o f degrees as 45°/division.
9. Measure the horizontal difference between corresponding
points on the waveforms.
10. M ultiply the measured distance (in divisions) by 4 5 °/
division (sweep rate) to obtain the exact amount o f phase
difference.
Example:
Assume a horizontal difference o f 0.6 division w ith a
sweep rate o f 4 5°/division as shown in Fig. 2-7.
Substituting the given values.
Phase difference = 0.6 division x 4 5 °/division.
Phase difference = 27°
High Resolution Phase Measurement
For phase differences less than 45°, measurement accuracy
is increased by using X I 0 sweep magnification as follows:
1. Perform steps 1 through 8 o f Dual-Trace Phase-Difference
Measurements.
2. Move the measurement points to the graticule horizontal
centerline.
3. Set the horizontal magnifier on. The sweep rate is now
4.5°/division (45°/division -f- 10).
4. Slightly readjust the horizontal position control to
move the measurement points w ith in the graticule area
(see Fig. 2-8).
C H A N N E L 1
C H A N N E L 2
M EASURE
T IM E FROM
A TO B
H O R IZ O N T A L
D IF FE R E N C E
4 6 5 /D M -0 -1 5
REV. A, O C T 1975
2-9
Fig. 2-7. Phase difference.
Fig. 2-8. High-resolution phase difference.
Summary of Contents for 455
Page 1: ...Tektronix 455 A2 B2 PORTABLE OSCILLOSCOPE WITH OPTIONS I N S T R U C T I O N M A N U A L ...
Page 9: ......
Page 13: ...455 A2 B2 x 455 A2 B2 Portable Oscilloscope ...
Page 61: ...Circuit Description 455 A2 B2 Fig 4 4 Channel switching gates REV A OCT 1975 4 9 ...
Page 66: ...Fig 4 6 Sweep generator 1C Function block diagram Circuit Description 455 A2 B2 ...
Page 80: ...Maintenance 455 A2 B2 BOTTOM FRAME Fig 5 7 VO LTS DIV switch disassembly 5 8 REV A OCT 1975 ...
Page 90: ...Maintenance 455 A2 B2 Fig 5 13 Troubleshooting chart 5 18 REV A O CT 1975 ...
Page 91: ...Maintenance 455 A2 B2 1907 1 A Fig 5 13 Troubleshooting chart cont REV A OCT 1975 5 19 ...
Page 132: ...Instrument Options 455 A2 B2 Option 7 Page 8 REV E AUG 1979 D C TO AC I NVERTER ...
Page 166: ...l 07 7 REV b NOV C M1 4 5 5 MAIN MODULE BLOCK DIAGRAM ...
Page 167: ...4 5 5 A 2 B 2 AS VERTICAL MODULE IR07 R8 RE V B M O ...
Page 168: ...I S 0 7 9 8 R E V B NOV IRT7 A2 VERTICAL MODULE BLOCK DIAGRAM ...
Page 169: ...REV B NOV 1977 Fig 9 2 A1 Partial Interface board compo ...
Page 170: ...455 A2 B2 Sea Parts List for serial number ranges tial Interface board component locations ...
Page 173: ...v I m B 2 HORIZONTAL MODULE BLOCK DIAGRAM ...
Page 174: ...455 A2 B2 REV B NOV 1977 Fig 9 3 A 1 Partial Interface board component locations ...
Page 182: ...455 A2 B2 Fig 9 4 A20 Vertical board component locations SN B0110 ...
Page 185: ...455 A2 S2 4 5 5 M A fN M O DULE ...
Page 187: ...455 A2 B2 Fig 9 5 A20 Vertical board component location SN B010100 B REV C NOV 1977 ...
Page 191: ...V O L T S 01 ...
Page 192: ...V O LT S Q IV S H O W N IN 57 H V ...
Page 198: ... U 1 X SlCjMAt TO P2 A4 h o p it MODULE SEE PARTS LIST FOR SEMICONDUCTOR TYPES f SWITCHING ...
Page 207: ...A 1 4 B T I M I N G S W I T C H B O A R D A13 A TIM ING SWITCH BOARD 1 9 0 7 3 ...
Page 209: ...4 5 5 A 2 B 2 B 2 h o r iz o n t a l m o d u l e R o i I 11 R E V C NOV IS77 ...
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Page 214: ......
Page 216: ...A B T IM IN G S W IT C H INTERFACE C O N N E C T O R ...
Page 223: ... ...
Page 224: ...455 A 2 B 2 ...
Page 225: ... 455 A2 B2 ...
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Page 233: ......
Page 234: ...455 A2 B2 ...