Giga-tronics 8501A, Operation & Maintenance Manual

Page: 173 / 262

7. Set the Start Delay to the value in the column to the right of the 26.5 ns that was selected in Step
6 above by moving the cursor to STRT DLY, entering the number (e.g. 0.0196 which is 0.0256
minus 0.006), and then pressing [
µ
s].
8. Set the Pulse Delay on the Signal Generator so that the rising edge of the pulse on the PPM
display crosses through the cursor at approximately the input pulse 50% point.
9. Set the Delay Window for 12 ns by moving the cursor to DLY WIND, entering [12], and
pressing [ns].
10. Set the Reference Power. Move the cursor to the REF PWR line and press [UNITS].
11. Adjust A5R30 (Vernier Delay) to its maximum ccw position.
12. The display should look similar to Figure 5-5.
13. Adjust A5R30 ccw until the rise time of the displayed pulse is smooth (see Figure 5-6).
14. Set the peak averaging number to 50 by pressing [MENU] (2) [F2] [50] [UNITS].
15. The rising slope of the pulse must still look smooth. If not, readjust A5R30.
16. Press [GRAPH].
Figure 5-5. Typical PPM Display with A5R30 at Max cw
Figure 5-6. Typical PPM Display w/Smooth Rise Time
Testing and Calibration
Manual No. 20790, Rev C, November 1998
5-17