Learn · 2 of 7 · 2 min
How a contact happens
Person to person, through a repeater, through a linked network, or over the long-distance bands. The same call, four very different paths.
Person to person: simplex
Two radios on the same frequency, nothing in between. On a handheld this reaches a few kilometres in the open and a few blocks between buildings; from a hill it reaches much further. This is the purest form and the one that keeps working when everything else is down. It is also the one newcomers try first and get nothing from, because nobody happens to be listening on that exact frequency at that moment. The where-am-I screen tells you who said they are around today.
Through a repeater
A repeater is a radio on a tall building or a hill that listens on one frequency and retransmits on another, so two handhelds that cannot hear each other can both hear the repeater. Your radio needs three things: the repeater's output frequency, the offset to its input, and often a tone (a sub-audible note that opens the repeater). Repeaters are owned by clubs or individuals, a trustee is responsible for each one, and most welcome anyone licensed. This is where most first contacts happen. The repeater page on this site gives you the settings, and the CHIRP download programs them into your radio.
Through a linked network
Many repeaters are joined over the internet, so a conversation on a repeater in Brooklyn is heard on a repeater in Perth. The links are made by systems such as AllStarLink and EchoLink for analogue radios, and by DMR, D-STAR and Fusion networks for digital ones. The internet carries the audio between sites, but each end is still a licensed operator on a real radio, and Part 97 rules apply the same. Some of these systems also let a licensed operator join from a phone app instead of a radio; that is what the "Connect from your phone" button on a repeater page does.
Over HF
The long-distance bands ("HF", roughly 3 to 30 MHz) bounce off the ionosphere, so a modest station reaches other continents without any infrastructure at all. Conditions change with the time of day, the season and the sun's activity. A General licence opens most of it. Voice, Morse and digital modes such as FT8 (which decodes signals far too weak to hear) all live here. This is where Parks on the Air and Summits on the Air get most of their contacts.
What a contact is, in words
Two stations exchange callsigns and confirm they heard each other. That is a QSO, the old telegraph code for "contact", and the name of this app. Most people log it, some confirm it with a QSL (a card or an electronic match on LoTW), and the awards programmes count them.