QSL Cards: The Postcards That Prove the Contact ON-AIR CRAFT | MORSE CODE WORKS Long before screenshots, radio had proof. After a contact, operators mailed each other postcards - QSL cards - printed with call signs, the date, the band and the report. A wall of QSLs from rare islands and famous stations became the operator's trophy cabinet and the hobby's paper memory. The system had its own postal service: QSL bureaus in each country collected cards and shipped them in bulk bundles to their destinations, a journey that could take a year and was worth every day of it. Today electronic confirmations settle the record in seconds - yet envelopes of paper cards still circle the globe, because a card you can hold is not data. It is evidence with a postmark. Key points - Design rule: your call sign must be readable across a shack - A card from a first contact is a document; operators keep them for life - Rare stations often confirm only by card - check their instructions - The bureau rewards patience the way the post always did Try it yourself Translate any text to Morse code and hear it with sound, free: morse code numbers 0 to 9