Chapter 2 83
Making Adjustments
12. Second Converter
Figure 2-20 Second Mixer Match Adjustment Setup
16.Set the microwave spectrum analyzer controls as follows:
CENTER FREQUENCY .......................... 321.4MHz
REFERENCE LEVEL .................................. −40dBm
SPAN .............................................................. 20MHz
dB/DIV ......................................................... 1dB/DIV
17.Adjust A5 2ND MIXER MATCH (refer to Figure 2-18) for maximum
amplitude as displayed on the microwave spectrum analyzer. Adjust
the reference level as necessary to keep the signal near top-screen.
Swept Bandpass Check
18.Set the analyzer controls as follows:
SPAN, 20, MHz
SWEEP, 20, SEC
19.On the microwave spectrum analyzer, press trace B and MAX
HOLD. Wait for at least one complete sweep. Then press the
following keys to measure the 3 dB bandwidth.
TRACE B VIEW
A ⇐⇒ B
PEAK SEARCH
MARKER MODE, ∆
20.Rotate the knob counterclockwise so that the marker delta
amplitude reads −3 dB.