A feed line with two conductors having equal but opposite voltages, with neither conductor at ground potential.

balance to unbalance , a device used to couple a balanced antenna to an unbalanced feed line (e.g., dipole to coax)

A range of frequencies allotted for a particular use (e.g., 20 Meter Band)

A large-value resistor connected across the filter capacitor in a power supply to discharge the filter capacitors when the supply is turned off.

Someone, usually not a Ham but a wannabe, making up a callsign, one usually not in the callbook, and getting on the air. Sometimes it is someone who already bought a radio, took the test and flunked, and then gets on the air anyway. Ham Radio Bootlegging is illegal.

(Repeater Term) used to interrupt a conversation on a repeater to indicate that there is an emergency or urgent message. If non-urgent, simply interject your callsign.

A semi-automatic mechanical code key.