A QSL card is a written confirmation of either a two-way radiocommunication between two amateur radio stations or a one-way reception of a signal from an AM radio, FM radio, television or shortwave broadcasting station. It can also confirm the reception of a two-way radiocommunication by a third party listener. A typical QSL card is the same size and made from the same material as a typical postcard, and most are sent through the mail as such.
A 1925 QSL card from amateur radio operator Bill Corsham, G2UV.
Amateur radio operators exchange QSL cards to confirm two-way radio contact between stations. Each card contains details about one or more contacts, the station, and its operator. At a minimum, this includes the call sign of both stations participating in the contact, the time and date when it occurred (usually specified in UTC), the radio frequency or band used, the mode of transmission used, and a signal report.
QSL cards are a ham radio operator's calling card and are frequently an expression of individual creativity — from a photo of the operator at their station to original artwork, images of the operator's home town or surrounding countryside, etc. They are frequently created with a good dose of individual pride. Consequently, the collecting of QSL cards of especially interesting designs has become an add-on hobby to the simple gathering of printed documentation of a ham's communications over the course of his or her radio career.
Normally sent using ordinary, international postal systems, QSL cards can be sent either directly to an individual's address, or via a country's centralized amateur radio association QSL bureau, which collects and distributes cards for that country.
Recently, the Internet has enabled electronic transmission as an alternative to mailing a physical card. These systems use computer databases to store all the same information normally verified by QSL cards in an electronic format. Some sponsors of amateur radio operating awards, which normally accept QSL cards for proof of contacts, may also recognize a specific electronic QSL system in verifying award applications.
Even in the presence of electronic QSLs, physical QSL cards are often fine historical or sentimental keepsakes of a memorable location heard or worked, or a pleasant contact with a new radio friend and serious hams may have thousands of them. Some cards are plain, while others are multicolored and may be oversized or double paged.