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2) In CAL MENU 1 (press BSP and TIME keys simultaneously), set
the FS700's attenuators for 64 dB. Look at the LORAN OUTPUT
on the scope in x-y mode ( to see the sweep). Make sure that the
notch filters are set to their extremes (40 and 220 kHz). Install
jumpers JP105, JP106, and JP107 (these are out in normal
operation).
2) Back L115 most of the way out. There should be two peaks in the
pass band. Adjust L113 and L114 so that these peaks are of equal
height and spaced symmetrically about 100 kHz at about 82 and
118 kHz. (See Figure 1.)
4) Adjust L115 so there is only a slight (~5%) dip in the passband.
L114 may need to be tweaked to remove any passband slope.
(See Figure 2.)
5) Remove JP105, JP106, and JP107. Stop the function generator
sweep.
6) Set the frequency to 78.8 kHz and adjust L116 for maximum
response.
7) Set the frequency to 120.5 kHz and adjust L117 for maximum
response.
8) Set the frequency to 100 kHz and adjust L118 for maximum
response.
9) Check the passband response using the test in the
PERFORMANCE TESTS section of the manual.
Figure 2.
Overall Bandpass Filter
Response
