Symmetricom 5071A, Assembly And Service Manual

Page: 33 / 202

1. Performance Tests – Verifying Specifications
5071A Complete Performance Tests
17
d. Press the “PEAK SEARCH” button, then the “MKR->REF LVL” button.
e. Set the resolution bandwidth (RES BW) to 300 Hz and the video
bandwidth (VIDEO BW) to 1 kHz.
NOTE The sweep time is 66.8 seconds. DO NOT adjust the sweep
time manually.
f. Press the “CONT” button in the sweep menu area to begin a new
sweep.
g. When the new sweep has passed through the fundamental frequency,
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.
h. When at least one sweep has completed, look for any signals that
appear on or above the
−
40 dBc display line at multiples of 100 kHz up
to 500 kHz. Use the knob in the marker area to move the offset marker
to any signals within this range if you want to measure or record these
signals. The marker shows the offset frequency and level in dBc from
the 100 kHz signal.
3 Record the actual reading in the appropriate place in the Performance Test
Record.