
14.
100
MHz
VCXO
Adjustments
Reference
RF-Section:
A7A2 100 MHz VCXO
Related Performance
Noise Sidebands Test
Tests
Residual Responses Test
Description
The open loop frequency and maximum power output of the 100 MHz
VCXO is centered around 100 MHz. The 400 MHz signal is adjusted for
maximum 400 MHz output with minimum spurious output. The 400
MHz output is set to -10
dBm
by selecting proper resistor values for
the attenuator network
A7A2R67,
R68, and R69.
Equipment
Procedure
Note
Frequency Counter
.........................................
HP 5343A
Spectrum Analyzer
.........................................
HP 8566B
Precision Power Supply
....................................
HP 6114A
Adapters:
Adapter, SMB (snap-on) (m) (m) . . . . . . . . . . . . . . . . . . . . . . . . . .1250-0672
Cables:
BNC to SMB Snap-On Test Cable (2
required) . . . . . . . . . . .85680-60093
The
A7A2
100 MHz VCXO Assembly must be installed in the RF
Section with all cover screws in place during this adjustment
procedure.
1. Position the spectrum analyzer on its right side as shown in
Figure 3-64, and remove the bottom cover.
FREWENCY
CCUNTER
PRECISION
DC
PWER
SUPPLY
SPECTRW
ANALYZER
Figure 3-64. 100 MHz VCXO Adjustment Setup
2. Set the spectrum analyzer LINE switch to ON. Verify that the
rear-panel FREQ REFERENCE switch is set to INT and that the
3-126 Adjustments
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