Conversion Section Adjustments - HP 3585A Service Manual

Model 3585A
5·33. CONVERSION SECTION ADJUSTMENTS
This section adjusts the filters associated with the first, second and third mixers. These filters
are of two basic types, peak and notch. Peak filters will be adjusted for a maximum
amplitude and notch filters for a minimum.
The Source used for these ad justments must be frequency locked
to the 3585A with the lOMHz REF OUTPUT�
All
top, bottom and side screws on the input section
place and tight be fore making these ad justments.
a. Turn the 3585A power off.
b. Set the 3585A on its left side and remove the bottom cover.
c. Adjustment of the Conversion Section requires its removal from the instrument;
therefore, disconnect all cables connected to the Input/Conversion Section.
d. Collect a stack of books approximately eight inches high. This stack of books will be
used as a support for the Input/Conversion Section.
e. Place the stack of books in the position shown in Figure 5-3 5 . Be careful not to touch
the high voltage section.
f. Remove the seven screws which hold the Input/Conv(�rsion Section in the instrument.
g. Carefully remove the input section by moving it toward the rear of the instrument until
the input connectors clear the front panel. Ensure that the BNC connectors do not damage
the front panel trim.
h . Place the Input/Conversion Section on the stack of books, bottom side down (Conver­
sion side up).
i. Connect a Spectrum Analyzer to the A50J1 90MHz output with the BNC-to-Sealectro
adapter cable. This output is located on the bottom side of the Tracking Generator Mother­
board.
j . Turn 3585A power on.
k . Verify that the 90MHz output level is + 1 5dBm ± 3dlB.
1.
Connect the Spectrum Analyzer to the A50J2 lOMHz output. This output is also
located on the bottom of the Tracking Generator Motherboard.
m. Verify that the l OMHz output level is + 1 8dBm ± 3dB.
n. Reconnect all cables to the Input/Conversion Section.
NOTE
NOTE
Adjustments
must be in
5-5 1