Chapter 2 55
Making Adjustments
5. Crystal and LC Bandwidth Filter
Final LC Centering
36.Press the following analyzer keys.
BW, 30, kHz
SPAN, 100, kHz
PEAK SEARCH, MARKER → CF
BW, 100, kHz
37.Make final adjustments by adjusting A11C23, A11C45, A13C23, and
A13C45 in succession to peak the amplitude of the marker at
center-screen.
38.Repeat step 36 and step 37 until the 30 kHz and 100 kHz
bandwidths are centered in relation to each other.
39.Press the following analyzer keys.
BW, 30, kHz
PEAK SEARCH
MARKER ∆
BW, 100, kHz
PEAK SEARCH
40.Verify that the MARKER ∆ frequency does not exceed 10 kHz.
If the signal shift is out of tolerance, repeat step 26 to step 39.
Crystal Amplitude
41.Press the following analyzer keys.
BW, 30, kHz
SPAN, 10, kHz
PEAK SEARCH
MARKER ∆
MKR FCTN, MK TRACK ON OFF (ON)
BW, 1, kHz
42.Adjust A11R31 XTL and A13R31 XTL equally for a MARKER ∆
amplitude reading of 0 dB. Each potentiometer should be adjusted to
accomplish one-half of the necessary increase in signal amplitude.
43.If A11R31 or A13R31 reaches its limit, recenter both potentiometers
and repeat step 41 and step 42.
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