Symmetricom 5071A, Assembly And Service Manual

Page: 29 / 202

1. Performance Tests – Verifying Specifications
5071A Complete Performance Tests
13
Specifications
All spurious nonharmonic signals must be <
−
80 dBc with respect to the
fundamental frequency.
Procedure
If you are using the HP/Agilent 3585B Spectrum Analyzer, follow the steps
below to test for spurious signals on the 5 and 10 MHz outputs. If you are
using a different spectrum analyzer, use these steps as a guide for operation
of that analyzer.
1 Connect the 5071A Port 1 to the 3585B analyzer as shown in
Figure 1-4. Set the 3585B for 50
Ω
input impedance.
2 On the 5071A, set output ports 1 and 2 to 10 MHz using the front
panel controls. See the section titled “Setting the Output Port
Frequency” in the 5071A Operating and Programming Manual for
instructions on how to do this.
3 On the 3585B, perform the following steps:
a) Press the green “INSTR PRESET” button and allow the analyzer
to go through its auto range algorithm (this will take about 5
seconds).
b) Press the “DISP LINE” (display line) button in the marker menu
and adjust the line to
−
80.0 dBc.
c) Press the “PEAK SEARCH” button and then the “MKR->REF LVL”
button (both are in the marker menu area).
d) Set both the resolution bandwidth (RES BW) and the video
bandwidth (VIDEO BW) to 1 kHz. Enter the 1 kHz values using the
numeric and unit keys. The RES BW and VIDEO BW values are
displayed at the bottom of the screen.
NOTE
The sweep time is 125 seconds. DO NOT adjust the sweep time
manually.
e) Press the “CONT” button in the sweep menu area to begin a new
sweep.
f) When the new sweep has passed through the fundamental
frequency, press the “PEAK SEARCH” button again. Then press
the “OFFSET” and the “ENTER OFFSET” buttons in the marker
menu area. Verify that both the offset frequency (Hz) and the
offset level (dB) go to zero (0 Hz and 0 dB should be displayed at
the top of the screen). If necessary, press and hold the “ENTER
OFFSET” button to zero-out the marker offsets.