Icom IC-746PRO Manual page 164

ANTENNA Selections
•
Antenna select function: "Auto"
– Once an antenna has been selected for use
with a band by pushing [ANT], the antenna
is automatically selected whenever that
band is accessed.
•
Antenna select function: "Manual"
– When "Manual" is selected, you can use
the [ANT1] and [ANT2], however, band
memory does not function.
•
Antenna select function: "OFF"
– In this case, only [ANT1] and the 144 MHz
antenna connector can be used. [ANT]
switch does not function.