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18. Frequency Control Adjustments
Full Sweep
11. Repeat Start-Up Time Measurement procedure in step 8 and step 9
Adjustment
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.
Note
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.
YTO and
VT0
DAC
15.
Adjustments
16.
17.
18.
19.
20.
21.
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).
Key in
Cm)
[CF
STEP SIZE)
J
0 MHz. The CRT annotation should
indicate DACS 0.
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.
Key in
(ml
[CF
STEP SIZE)
J
1023 MHz. (CRT annotation may still
indicate DACS 1023.)
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.
On the HP
3456A,
Press
INIATH_)
@
OFF.
Connect DVM to
A22TP9.
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