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Method Three:
1) Start the FS700's search. Look at the LORAN OUTPUT on a
normal scope with the horizontal speed set so that an entire GRI fits
onto the screen.
2a) If the interfering signal is so big that it is the only thing visible on the
scope, adjust the notch filters so that the interfering signal is
minimized.
2b) Otherwise, wait until the FS700 has locked and adjust the notch
filters to minimize the "fuzz" or noise between the pulses of the
selected station.
Search Problems
In general, it is best to set both station selection and search mode to
AUTO. The FS700 will then always pick the strongest signal and
automatically restart after errors. Although the FS700's station search
is usually uneventful, a variety of problems can occur during the search
and identification phase of station acquisition. In all cases, if the FS700
fails to acquire the correct station, the best thing to do is try again. This
is because the most common problem is some type of transient
interference confuses the FS700. The detectable errors during the
search phase are:
No Stations Found -
This error means that the FS700 is
unable to detect anything that resembles
a LORAN station. If this happens, check
to see that the GRI is set to the correct
value and that the antenna is functional.
Too Many Stations Found -
This error occurs if the FS700 detects
too many signals that resemble LORAN
pulses. This can occur in areas of very
high interference. If the interference is
locally generated, moving the antenna
can reduce the effect. Also, the FS700's
notch filters may be used to eliminate
strong out-of-band signals.
No Master Station Found -
This error occurs if no master station
(station with nine pulses) is detected. In
AUTO station select mode, the FS700
will still pick the largest station and
function normally. The station
identifications will just be unknown. The
absence of the master does not affect
tracking performance. If a specific
station is selected, the station can not be
identified and the search will be
terminated.
