5-14.
UNLEVELED RF OUTPUT ADJUSTMENTS (Cont’d)
33. Press the following key sequence on
the OUT:
For an HP 8340B
[INSTRPRESET]
[STARTFREQ] [1] [9]
[.1
[8] [GHz]
[XTAL]
[SWEEPTIME][2] [0] [0] [msec]
[SAVE][1]
[SWEEPTIME][AUTO]
[SAVE][2]
[SINGLE]
[SAVE][3]
[RECALL][2]
For an HP 8341B
[INSTRPRESET]
[STARTFREO] [1] [3]
[.1
[3] [5] [GHz]
[XTAL]
[SWEEPTIME][2] [0] [0] [msec] (500 inS if the OUT has Option 003)
[SAVE][1]
[SWEEPTIME][AUTO]
[SAVE][2]
[SINGLE]
[SAVE][3]
[RECALL][2]
34. Adjust the scope’s vertical and horizontal sensitivity to view the swept display. The horizontal gain
should be set so the trace covers the full display from left to right.
35. Access Calibration Constant 75 by pressing the following key sequence on the OUT:
[SHIFT][GHz][7] [5] [Hz]
[SHIFT][MHz] [1] [2] [Hz]
[SHIFT][kHz] [2] [2] [Hz]
NOTE
The range for the delay compensation Cal constants, numbers 2 through
8, is 0 to 131. If the Cal Constants do not provide sufficient range for the
delay compensation, Cal Constant 8 should be lowered (Cal Constant 7
for the HP 8341 B)
,
A28R22 (DYO) and A28R19 (DYS) readjusted, and then
the SYTM DELAY COMPENSATION ADJUSTMENTS BY BAND procedure
should be repeated.
36. Adjust A28R22 (DYO) for optimum power in the first half of the display. Ignore the small power
dropout at the beginning of the sweep, this will be eliminated later.
37. Adjust A28R19 (DYS) for optimum power in the second half of the display. Iterate between steps
36 and 37 until optimum power is achieved across the band.
38. Using the OUT’s rotary knob, adjust Cal Constant 75 (range is 0
to
500)
to
optimize the power in
the first division (left hand side) of the display (i.e., eliminate the small power dropout).
Adjustments
5-81
HP 8340B/41B