Tektronix 1780-R Simultaneous Diff Phase & Diff Gain Measurements

Measurements

4–12 1780R-Series Operator’s Manual

Simultaneous Diff Phase & Diff Gain Measurements

Enter DP & DG Mode

Push the MEASURE button to enable the Measurement menu,

shown in Figure 4–1.

Touch <DP & DG> on the screen to enable simultaneous differential

phase and differential gain measurements.

The DP & DG menu is displayed on the left CRT, and the demodu-

lated sweep is displayed on the right CRT. See Figure 4–4.

The instrument is now configured as specified in Table 4–3.

Exit DP & DG Mode

To exit DP & DG mode, push the MEASURE button again. All

instrument settings return to previous state.

Horizontal positions, vertical positions, and gain settings defined

while in DP & DG mode will be stored when exiting, and reinstated

when this mode is selected again.

DP & DG Menu Selections

Noise Reduction. Touch <NOISE REDUCTION> to toggle between

<ON> and <OFF>. When noise reduction is off, the demodulator

output (500 kHz BW) is directly displayed. When noise reduction is

on, noise reduction of about 10–12 dB is accomplished without any

reduction in bandwidth.

Freeze. To capture the display (right CRT only), touch <NOISE

REDUCTION> so that <ON> is outlined, then touch <FREEZE>.

<FREEZE> will be outlined.

The captured display remains on the screen even if the input signal is

removed. The display is lost when the DP & DG menu is exited by

any method, including pushing any of the four front-panel menu

buttons, pushing the front-panel LINE SELECT button to enter Line

Select mode, changing the selected line if already in Line Select

mode, or turning instrument power off.

To exit Freeze mode, touch <FREEZE> again.