Tektronix 1740A Series, Руководство пользователя

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Performance Verification
1740A/1750A/1760 – Series Service Manual
4–35
g. Check – the display for a locked sine wave.
h. Set the function generator frequency to 90 Hz.
i. Check – the display for a locked sine wave.
j. Remove the function generator output and the Remote Cable Adapter
from the 1740A/1750A/1760–Series.
34. Return Loss
Requirement – Video Inputs: 40 dB to 6 MHz. Power on or off. Pix
Out: 30 dB to 6 MHz. Power on.
NOTE
. Return Loss Check:
The Return Loss Check needs to be done only if repairs have been made on the
Input circuitry.
a. Enter the Preset menu and select RECALL FACTORY.
b. Connect a precision 50 cable from the spectrum analyzer RF Input to
the RF Output on the RF Bridge.
c. Connect a precision 50 cable from the spectrum analyzer TG Output to
the RF Input on the RF Bridge.
d. Select Demod/TG on the spectrum analyzer. Turn on the tracking
generator and set the tracking generator fixed level to 0.00 dBm.
e. Set the spectrum analyzer Span/Div to 1 MHz and the Resolution
Bandwidth to 3 kHz.
f. Set the spectrum analyzer Reference Level to the first major division
down from the top on the analyzer display.
g. Set the spectrum analyzer Vertical Scale to 10 dB.
h. Remove one of the cables from the RF Bridge.
i. Set the spectrum analyzer Frequency to 5 MHz, turn on the Marker, and
then set the Marker to 6 MHz.
j. Reconnect the cable to the RF Bridge.
k. Note – the Reference Level Readout.
l. Adjust the spectrum analyzer External Attenuation Amplitude (on the
2712 Input menu) by the amount noted in the previous step. Note: The
Reference Level Readout should now be 0.00 dBm.
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