Because it’s illegal.
I just thought I’d throw that out there for those that were confused or misdirected…
Before I had even taken my ham license test, I was given an old Icom radio to muck about with. As it turned out I found a fairly busy repeater in the East Bay (K6POU) that was quite fun to listen to. It continues to be the busiest repeater, on a regular basis, that I’ve found. As the group that hangs out on the repeater is a fairly loose bunch they end up chatting about a lot of different topics. More than a few times I found those topics and questions right up my alley, and was wanting to respond.
Unfortunately I wasn’t licensed, so I couldn’t. It was suggested to me by a friend that I should get on anyways, after all “what’s the big deal?”. Well it sorta is a big deal; it is illegal to transmit on (almost) all frequencies without a license (be it your own or a companies you work for). Being realistic, the FCC isn’t going to bust down your door if you do, in all likelihood you could do it dozens of times and the FCC/Cops aren’t going to do squat about it. So why don’t you do it?
People know. Even listening to the radio for only a week or so, I had started to recognize all the regular voices on the repeater. These people on the repeater are there every day and most definitely know everyone else’s voice. If you get on, they will know instantly that you are new. Especially if you are new to amateur radio, you’ll give yourself away with incorrect procedure. Most importantly, everyone expects a callsign, if you don’t give one — they’ll ask.
If you lie yourself a callsign, you better get real lucky. The instant you give your call on a repeater like K6POU which is busy, a half dozen people will have looked you up. If you gave a call that isn’t in the system, they are going to know. If you gave a real callsign of someone else, you better hope it isn’t someone they know. Remember, the hams are a fairly small and friendly group — they’ve QSL’d people across the entire world (shortwave FTW). It is entirely possible that at least one person on the repeater has talked to the callsign you’re stealing.
If you do get lucky, then you better hope that any of the people you talk to don’t decide to send you a QSL card. The cards are, many times, done via the internet. I know if I got a QSL card from someone I never talked to, I’d write back asking them what was up. Of course the jig would be up for you, the callsign stealer.
In the end, you’ll get found out and instantly earn yourself a blackmark. You’re now a repeater pariah. Again, they’ll recognize your voice if you get back on. So even if you go legit and try to come back, they’ll probably remember. They won’t talk to you and probably run you off the repeater. How do I know? I asked the guys on K6POU the first night I got on. I explained to them my dilemma of wanting to get on but not having a license and they explained to me (very kindly) what has happened to others. Oh, and the first night I got on, they ran my call and couldn’t find me in their regular databases. I had to explain that I was only in the FCC’s at that point. Just to show that people WILL run any and every call that comes on the air.
If you want to get on the radio: Get a license. The test takes less than an hour and only costs $15. You could cram for it and potentially have your very own call in a week (depending on FCC speed). Hams really are a friendly group and so far everyone I’ve talked to has been very nice. They only ask that you follow the rules. It might seem a little complicated to the uninitiated but it really isn’t that hard. Any ham will be happy to help you get going, or direct you to someone that can help you.