Performance Tests
Model 3585A
4-1 6
4· 1 8. 1 M ohm Input Impedance Test
These tests verify that the 3585A meets the Input Impedance specifications for the 1 MO, 30
pf Input Impedance setting.
Specification:
1 MO ± 3 070 ,
<
30 pf
Equipment Required:
Resistor:
1 MO ± 1 % , 1 I8W Film . . . . . . . . . . . . . -hp- Part No. 0757-0344
500 Feed Thru Termination . . . . . . . . . . . . . . . . . . . . . . -hp- 1 l048C
Synthesizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -hp- 3335A
Procedure:
a. Set the 3585A controls as follows:
INSTRUMENT PRESET
CENTER FREQUENCY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 kHz
MANUAL SWEEP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . on
RES. BW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Hz
RANGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . O dBm
INPUT IMPEDANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 MO
b . Connect the 500 termination to the 3585A 1 MO input. Connect the synthesizer output
to the termination input.
c. Set the synthesizer controls for:
FREQUENCY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 kHz
AMPLITUDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 dBm
d. Set the 3585A controls for OFFSET on. Allow time for the marker reading to
stablize,then press the ENTER OFFSET button.
e. Using short clip leads, insert the 1 MO resistor between the output of the termination
and the 3585A 1 MO input as shown in Figure 4-3 . 1 M Ohm Input Impedance Test.
f. The 3585A marker amplitude reading should be -6.0 dB ± 0.44 dB, verifying that the
input resistance is 1 MO ± 5 % .
g . Press the 3585A ENTER OFFSET button.
h . Set the synthesizer frequency to 10 kHz.
i. Set the 3585A for a CENTER FREQUENCY of 10 kHz.
j . The 3585A marker reading should be between -2 dB and -3 dB, verifying that the shunt
capacitance is less than 30 pf.
Summary of Contents for 3585A
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