HP 3336A - Page 144

Adjustments Model 3336A/B/C
These values are set by adjusting the dc offset and gain of the amplitude reference amplifier. a
fi i
Required Equipment: \
ac voltmeter -hp- Model 3455A with Option 001
or -hp- Model 3490A
50 ohm feedthru termination -hp- Model 11048C
75 ohm feedthru termination -hp- Model 11094B
75 ohm cable ,
NOTE
The 3336 must be ON 30 minutes before attempting this adjust-
ment.
a. Connect the ac voltmeter to one of the unbalanced outputs, using the proper feedthru
termination at the voltmeter’s input.
1,
23lAm
50.su.
b. Set the output amplitude to — 2.99 dBm using the 75 ohm output. Set the frequency
to 10 kHz.
(S85 Vas t.S a
c. Adjust A4R259 until the ac voltmeter reads\.1941 Vrms, +.5 mV.
B76 dtm,
d. Set the output amplitude to + 7.00 dBm.
5006 Uy, tl mv
e. Adjust A4R261 until the ac voltmeter reads{.6130 Vrms, +1 mV.
f.
Repeat
Steps
b
thru
e
until
both
voltages
are
within
their
tolerances.
Go
to
Step
h
if
it
is
iy
not
possible
to
set
these
voltages.
g. Set the output amplitude to +3.00 dBm.
BIS9 F im
h.
The
ac
voltmeter
should
read
.3868
Vrms,
+1
mV.
If
this
voltage
is
out
of
tolerance,
perform the following adjustments and ther try this adjustment again.
¢ Multiplier Input and Output Offset (5-17)
e —10.2 Vdc Reference Voltage (5-21)
® DAC Offset Voltage (5-23)
¢ Leveling Loop Amplifier Zero (5-25)
e Leveling Loop Bias (5-27)
5-31. Output Amplifier Flatness Adjustment.
5-32. This adjustment optimizes the ac feedback in the output amplifier, insuring the flattest
possible frequency response.
Required Equipment:
oscilloscope -hp- Model 1740A
50 ohm feedthru termination -hp- Model 11048C
75 ohm feedthru termination -hp- Model 11094B
5-10