HP 8568B manual Full Sweep Adjustment, YTO and VT0 DAC Adjustments

Full Sweep

Adjustment

Note

YTO and VT0 DAC Adjustments

18.Frequency Control Adjustments

11.Repeat Start-Up Time Measurement procedure in step 8 and step 9 for (SWEEP TIME) of 20 ms. Note value of measurement.

20 ms start-up time:

12.Key in [Shift_) CREssWr three times and note the CRT annotation. The annotation should indicate SWEEP GEN measured sweeptime of (20 ms + start-up time noted in step ll)*O.l ms. If it is not in spec, determine the difference between this measured sweep time and the target sweep time of 20 ms + start-up time noted in step 11.

(measured sweep time) - (20.00 ms + start-up time) =

13.Adjust A22R91 FAST for three times the difference; and in the opposite direction, as noted in step 12. See note below. Adjust A22R91 slightly then key in [SHIFT) [REsy and note new SWEEP GEN measured sweep time as indicated by CRT annotation. Repeat this process until the 20 ms sweep time is set to the value calculated in this step.

Adjusting A22R91 CW increases the sweeptime. If the difference between the measured 20 ms sweep time and the target sweep time is less than approximately 0.3 ms, adjust A22R91 for the target sweeptime. Adjusting A22R91 to 3 times the difference noted in step 12 is only needed if the difference noted in step 12 is greater than 0.3 ms.

14.Repeat the adjustments in step 8 through step 13 until the measured sweep time at 20 ms is 20 ms plus the Start-Up Time measured in step 11 (fO.1 ms) and the measured sweep time at 1 s is 1.00 s plus the start-up time measured in step 8 (50.01 s).

15.Key in Cm) [CF STEP SIZE) J 0 MHz. The CRT annotation should indicate DACS 0.

16.Connect DVM to A22TP6 and ground to A22TP12. If using an HP 3456ADVM,press(STOREI(?JZ,(ENTEREXP)y,@,cm)(81

‘, then INIATH_), (?J (X-~/Y. If not using an HP 3456A DVM, note voltage indication for reference later.

17.Key in (ml [CF STEP SIZE) J 1023 MHz. (CRT annotation may still indicate DACS 1023.)

18.Adjust A22 YTO A22R25 for DVM indication of + 10.230 kO.001 V dc. If not using an HP 3456A DVM, adjust for specified voltage plus the DVM indication noted in step 16. See Figure 3-71 for location of adjustment.

19.On the HP 3456A, Press INIATH_) @ OFF.

20.Connect DVM to A22TP9.

21.Key in [SHIFT) [CF STEP SIZE) J 0 Hz. If using an HP 3456A DVM, pressISTORE_)@Z,~@Y,@,(STORE)@Y, then (MATH_), 0 (x-z),y. If not using an HP 3456A DVM, note voltage indication for reference later.

Adjustments 3-121