HP 8340B Manual page 315

5-17.
RF
OUTPUT POWER FLATNESS ADJUSTMENT (Cont'd)
9.
Set the
power meter's CAL FACTOR %
dial
to 100%. Press [RECALL] [1]
on the OUT. Set the
oscilloscope for maximum
PERSISTENCE
and minimum
BRIGHTNESS.
On
the DUT, Press
[SHIFT] [GHz] [1] [4] [Hz] [SHIFT] [MHz] [1] [2]
[Hz] [SHIFT]
[kHz] [2] [2] [Hz]
to
access
Cal
Constant
14.
NOTE
Refer to Figure
5-62
to determine the effect the following adjustments
have
on the flatness of the RF output.
NOTE
The bandcross points seen on the oscilloscope can be used as
a fre¬
quency reference for the following adjustments. The frequency of
the
bandcross points are,
from left to right,
7.0,13.5, and
in the case of the
HP 8340B,
20.0 GHz. The bandcross
points
are the points at which the
sweep pauses and the power
drops to
a
minimum for an instant
Adjust Cal
Constant
14 for the flattest trace from 2.4 to 9
GHz
Press the
DUT's
[*•]
step key to access Cal Constant 15 and adjust Cal
Constant
15 and A27R4
(BK PT1) for the
flattest trace from
9 to 20 GHz.
If adjusting an HP
8340B, press the DUT's [^] step key to access Cal
Constant
16.
Adjust
Cal
Constant
16 and
A27R8 (BK PT2) for
the flattest trace from 20 to 26.5 GHz.
Repeat these adjustments
until the flattest trace
is
obtained from 2.4 to the maximum
DUT RF
Output frequency.
BREAKPOINT
1
POT
2.3QHZ
9QHZ 19GH2 20GHZ
Figure 5-62.
Relationship of Flatness Adjustments
Diagram
HP 8340B/41B
Adjustments