Got my Tech license a few weeks ago and picked up a Baofeng UV-5R to get started. I can hear my local repeater crystal clear - 146.82 with a minus offset. But when I try to transmit, nothing happens - the repeater doesn't key up at all. Am I missing something obvious here? I've triple checked the frequencies and offset. Maybe it's the PL tone? The repeater directory shows 110.9 Hz but I'm not sure how to set that on this radio.

Any help would be appreciated - feeling pretty dumb right about now!

Welcome to ham radio! You won't be able to access the repeater if you're not also transmitting the CTCSS tone the repeater has been programmed to respond to. On your UV-5R, you'll need to program that 110.9 Hz tone as your transmit PL tone - check page 15 of your manual for the T-CTCS setting.

Had the exact same problem with my first HT! The tone is definitely your issue - if you're not hitting a repeater when you think you should be, first check to see that you're transmitting the correct CTCSS tone. Don't feel dumb, we've all been there.

Also worth noting that you may hear CTCSS tones sometimes called PL tones. PL is short for "private line," and is what Motorola, the company that developed the CTCSS system called it. Since PL is a Motorola trademark, we now use the generic term CTCSS. Same thing, different names.