ok so ive been licensed for about 3 months now (Tech) and i finally got a Baofeng UV-5R which i know everyone has opinions about but its what i could afford. anyway i programmed in the local 2m repeater from the repeater directory and i can hear other people talking just fine but when i key up nobody seems to hear me or acknowledge me at all. i sat there for like 20 minutes during what sounded like a pretty active net and said my callsign a few times and crickets.

someone at my club meeting last week mentioned CTCSS tones and i think thats probably my problem but honestly i dont fully understand what they are or how they work. like i get that its a subaudible tone you transmit but does the repeater need a specific one or is there a standard? and how do i even know which tone to use for a specific repeater if its not listed in the directory entry i found?

also is there like a rule about how you break into a conversation thats already going? i dont wanna be that guy who just steps on people mid-sentence. any help appreciated, still trying to figure all this out

yeah CTCSS is almost definitely your issue. most repeaters require you to transmit a specific subaudible tone so the repeater knows to open up - without it your signal just gets ignored by the repeater's controller even if your audio is coming through perfectly. its not a standard tone, every repeater can be set to whatever the trustee wants, common ones are like 100.0 or 127.3 or 88.5 Hz but really it could be anything.

best bet is to check the repeater's listing on repeaterbook.com rather than whatever directory you were using, they tend to be more up to date and usually show the PL tone right in the listing. if its still not listed you can try reaching out to the club or trustee listed for that repeater, most people are happy to help a new ham get on the air.

as for breaking into a QSO that's already going - you just wait for a pause between transmissions and say your callsign. like literally just say your call during the gap. most operators will acknowledge you and invite you in. its pretty relaxed on most repeaters, dont overthink it. the main thing is dont kerchunk the repeater (just keying up with no audio) and dont talk over someone mid-sentence and you'll be fine.

oh man i had the exact same problem when i started out lol. spent like a week thinking my radio was broken. turns out the repeater i was trying to use needed 107.2 and i had no tone programmed at all. once i fixed it everything just clicked. repeaterbook is your friend for sure, that site has saved me more than once.

one thing i'll add - some repeaters are open and dont require a tone at all, so if you find one like that nearby its a good way to test that your radio is actually working before you mess around with CTCSS settings. that way you at least know its not a power or antenna issue or whatever.