Fluke 271 manual Asymmetric waveforms, Adjusting the phase, Getting Started

Models: 271

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Asymmetric waveforms

Getting Started

Using the Instrument

Asymmetric waveforms

Symmetry adjustments work in much the same way as dc offset adjustments. However, because of the lengthy calculations which the instrument makes following a change to the symmetry setting, you may find it easier to use direct numeric entry rather than the rotary control.

Again, the symmetry of the output is displayed in brackets at the right of the programmed value and in certain circumstances the programmed and actual values may differ. For example, at high output frequencies the specification limits for symmetry are 20 to 80 % for a square wave but 1 to 99 % for a sine wave. Full details are given in the Specifications section in chapter 1 of the Users Manual.

Adjusting the phase

The AUX OUT socket supplies a TTL and CMOS- compatible (0/+4 V) reference signal against which you can adjust the phase of the signal at the MAIN OUT socket.

Return to the factory default settings by pressing RECALL, 0, ENTER, then press the EDIT key followed by

TRIG.

The lamp next to the TRIG key will flash and you should see a screen like this:

SOURCE=EXT

TGEN=1.00ms 1.000kHz

BURST COUNT= 0001

PHASE=+000° (+000°)

The instrument is still operating in continuous, not triggered mode, so the settings for the trigger source, the internal trigger generator and the burst count are not relevant here. The only item on this menu which affects continuous modes as well as triggered and gated modes is the PHASE setting.

Move the cursor to the last digit of the phase numeric value field and use the rotary control to move the phase of the AUX OUT relative to that of the MAIN OUT.

SOURCE=EXT

TGEN=1.00ms 1.000kHz

BURST COUNT= 0001

PHASE=+116° (+116°)

You may want to trigger the oscilloscope from the

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Page 25
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Fluke 271 manual Asymmetric waveforms, Adjusting the phase, SOURCE=EXT TGEN=1.00ms 1.000kHz BURST COUNT= PHASE=+000 +000