What Does 73 Mean?
By NP4H Mission Control
In amateur radio, 73 means “best regards.” It is one of the most recognized traditions in the hobby and is commonly used at the end of a QSO.
The expression comes from early telegraphy, where numbers were used as shortcuts for common phrases. Today, operators around the world still close contacts with a simple and friendly “73.”
A clean way to use it is: “Thanks for the contact. 73 from NP4H.”