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Digital Radio Testing
1-40
of the spectrum sent through the Fader. You may
want the power level to remain constant even though
you have a notch. If you are interrupting the digital
radio after its own internal ALC or AGC circuitry,
you may have to use the Fader's internal AGC
circuitry to prevent non-fade e ects from distorting
measurement results. Press
key to display AGC ON if AGC OFF is displayed.
Press
to exit.
4 ENTER 5
8. The display should now read
AGC is ON, you should ensure that you have the
proper AGC center frequency set. Press
and the display will change \
whatever frequency may have been set previously.
Use the arrow or data keys to set the desired
frequency, then press
9. The display should now read \
allows you to set the bandwidth to distribute the
AGC power over. Press
this is set to. Use the arrow or data entry keys to
set a value. Use a value close to the radio's channel
bandwidth, then press
10. The display should now read \
allows you to set the wait time after every notch
movement. This wait allows your radio some settling
time before a Bit Error Rate measurement is made
by the Fader. Press
set to. Use the arrow or data entry keys to set a new
value if desired, then press
11. The display should now read \
allows you to set the notch's maximum slew rate
during measurements. Press
value this is set to. Use the arrow or data entry keys
to set a new value if desired, then press
12. If you want to test bit error rate when a notch
exists in the IF path (or some other path), press
HP 11757B
, then use the
4 ENTER 5
5 AGC FREQ
4 ENTER 5
AGC FRQ 070.0
.
4 ENTER 5
". This
6 AGC BW
to see what value
4 ENTER 5
.
4 ENTER 5
7 WAIT TIME
to see what value this is
4 ENTER 5
.
4 ENTER 5
8 MAX SLEW
to see what
4 ENTER 5
4 ENTER 5
485
. If the
" or
". This
". This
.
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