General Dynamics R2600 Series, Operator'S Manual, Page: 94 / 402

by moving it within the RF memory table to a
location just above or below the preset numbers
being scanned.
It is recommended that frequencies in the RF
memory table be grouped according to their
modulation type and bandwidth because these
parameters must be manually changed in the
analyzer's RF Control zone. If an AM frequency
(e.g. aircraft band) is intermixed with FM
frequencies (e.g. public service band) in the scan
list and the analyzer is set to FM mode, radio
traffic on the AM frequency will cause the
scanner to lock, but the received audio will be
unintelligible and the modulation measurement
meaningless.
Because breaking the receiver squelch causes the
analyzer to stop scanning, it is important to
properly adjust the squelch control. If the
squelch is adjusted too loosely (counterclockwise
rotation of the squelch knob), it is possible that
desired signals will not be strong enough to break
the squelch and the analyzer will not stop and
dwell on the channel. To adjust the squelch
control for proper scanning operation, turn the
squelch control fully counterclockwise and
activate the Preset Scan mode. The analyzer will
not scan because it will lock on the first
frequency due to the squelch being open. Now
slowly rotate the squelch control clockwise, just
until the squelch light goes out, the noise in the
speaker stops and the unit begins to scan. If an
actual signal is received while the squelch is
being adjusted, wait until it ends before resuming
the adjustment. For maximum sensitivity, the
squelch level should be adjusted as loose as
possible (counterclockwise) without being broken
by receiver noise.
To halt the scanning operation at any time, press
the
RF DISPLAY softkey. This stops the scanning
process and leaves the analyzer locked onto the last
scanned frequency prior to the key press.
NOTE
When the unit is in the Preset Scan mode, the
response time to key presses will be somewhat
slower than normal. For best results, it is
recommended that you do not leave Preset
Scan active when it is not being used.
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