1Mo Amplitude Adjustment; Mo Flatness Adjustment - HP 3585A Service Manual

Model 3585A
5·41 . 1 MO Amplitude Adjustment
a. Terminate the IMO 3585A input with a 500 feedthrough termination. Move the syn­
thesizer output from the 3585A 500 input to the 500 termination on the IMO input.
b. Press the IMO IMPEDANCE key on the 3585A.
c. Adjust A I R108 for a marker amplitude reading of -25.20dBm.
5·42. 1 MO Flatness Adjustment
a. Connect a IOdB/step attenuator to the output of the Tracking Generator. Connect the
output of the Attenuator to the 500 termination on the IMO input.
b. Set the attenuator for 40dB of attenuation.
c. Turn the Tracking Generator Amplitude control fully clockwise.
d. Set the 3585A controls for:
e. Move test jumper A15Wl to the "TEST" position.
f. Using the Continuous Entry Control, adjust the REF LVL so that the trace is centered
on the display.
g. Press STORE A - B on the 3585A.
h. Set the 3585A to the -5dBm RANGE.
i. Set the external attenuator for 20dB.
j . Adjust A I C2 1 so that the A trace overlaps the B trace as closely as possible (see Figure
5-42).
k . Set the 3585A for the + 1 5dBm RANGE.
1.
Set the external attenuator for OdB.
m. Adjust AIC2? so that the A trace overlaps the B trace as closely as possible.
n. Move test jumper A 1 5Wl back to the "NORM" position.
INSTRUMENT PRESET
IMO IMPEDANCE
START FREQUENCy . . . . . . . . . . . . . . . . . . . . . . . l kHz
STOP FREQUENCy . . . . . . . . . . . . . . . . . . . . . . 1 00kHz
RANGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -25dBm
AUTO RANGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . off
dB/DIV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2dB
Adjustments
5-65