5-18.
PULSE ADJUSTMENTS (Cont’dJ
3. Set the pulse generator for a pulse width of 4 microseconds, a pulse period of
10
microseconds,
and amplitude
=
+3
Volts high and 0 Volts
low. Remember that CHAN B is inverted and X5 MAG
is on.
4. On
the OUT, press [INSTRPRESET]. Press
[PULSE]ON. Press [CW]and enter [5]
[GHz].
Press
[SHIFT][PWRSWP] and enter [0] [dBm]. Use the step keys to step in 10dB RF attenuation. If the
OUT does not include an RF attenuator, connect a 10
dB
pad to the
RF
output. Set A21R45 (ON
DELAY-INT), A21R47
(OFF
DELAY),
and A21R44 (ON DELAY-SYS) fully counterclockwise. (See
Figure 5-65.)
Check that the OUT is leveled (the UNLEVELED light is not lit).
5. Set the oscilloscope to 1
usec/Div. the CH A trace should be similar to Figure 5-66.
6. Adjust A25R58 (BAL) control for best continuity (flat line) across the pulse trailing edge. (NOTE:
A25 must not be on
an extender board when viewing trace.).
SAMPLE AND HOLD TIMING ADJUSTMENT
7. Set the pulse generator for a pulse width of
120
nanoseconds.
On
the OUT, press [SHIFT][PWR
SWP] and enter
[—]
[1] [0] [dBm]. Then press [SHIFT] [SLOPE]and use the
[STEP]keys to set
attenuator to —10 dB.
8. Connect the DVM to A26TP3 (MOO
LVL).
Adjust
A21R45 (ON DELAY-INT)
and
A21R47 (OFF
DELAY) for the most negative reading.
9. Set the OUT controls as shown below:
a
Press [SHIFT] [PWRSWP] and use [STEP] keys to set attenuator to —10
dB.
b.
Use keys to enter [0][dBm].
c.
Press [CW]and enter [5]
[GHz].
10. Set the oscilloscope to 0.2
usec/OIV and adjust the Pulse Generator to a 1 usec pulse.
ADJUST FOR SAME LEVEL.
Figure 5-66.
Typical A26TP2 (DET) Pulse Waveform.
5-124
Adjustments
HP 8340B/41B