Icom IC-7400 Instruction Manual page 11

d. Filters:— continued
• On the fly adjustment: Once the adjustments have
been made in the filter set mode, you can make on
the fly changes by using the Twin Pass Band Tuning,
Twin PBT. You will be able to see the effects of the
Twin PBT on the upper left hand side of the screen.
One of "1," "2" or "3" is
displayed for selected filter
number indications.
NOTE: The Twin PBT filters shift the two IF DSP
filters (See Diagrams below and right). This feature
allows both an IF shift as well as a narrowing of the
Pass Band. Although you can narrow the pass
band by shifting the two filters, this does not nar-
row both filters, thus the filter shape is not nar-
rowed. You may hear some signal artifacts pass
through this filter adjustment.
Center
IF center frequency
Passband
pass band
desired signal
interference
PBT operation example
Passband width and shifting value are
indicated while [TWIN PBT] is operated.
• Filter set mode indication
Shows the selected filter and passband width.
• Indication while PBT setting
Appears when passband is shifted.
*By pushing [PBTC] for 1 sec., the shifted value returns
to the default setting, and the "dot" disappears.
Passband
desired signal
inteference
QUICK REFERENCE GUIDE
[TWIN PBT] control
[PBTC]
Appears when PBT is used.
IF shift
IF center freq.
interference
VIII