146.52 MHz gets programmed into practically every 2 meter radio sold, but a lot of new hams never get a clear explanation of what it’s actually for or how to use it without annoying everyone listening.
What 146.52 actually is
146.52 MHz is the nationally recognized 2 meter simplex calling frequency in the US, meaning it’s the agreed-upon spot where hams listen for someone trying to make initial contact without going through a repeater. It’s simplex, radio to radio directly, no repeater infrastructure involved, which limits range to roughly line of sight but also means it works even if every repeater in the area is down.
Other simplex frequencies worth knowing
446.000 MHz plays the equivalent role on 70cm, and a handful of other recognized simplex frequencies exist across 2m and 70cm for specific purposes, including designated simplex repeater backup channels used during ARES and RACES operations when repeaters aren’t available. Knowing these ahead of time, rather than scrambling to look them up during an actual event, is exactly the kind of small preparation that pays off.
The etiquette that actually matters
146.52 is meant to be a calling frequency, not a hangout channel. The convention is to call, make contact, and then move to a different simplex frequency to actually have your conversation, keeping the calling channel clear for the next person trying to establish contact. Monitoring 146.52 while mobile or at home costs nothing and occasionally rewards you with an unexpected contact, but parking a long conversation there is generally considered poor form.
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