so ive been licensed for about 3 months now and i jump on the local repeater sometimes but ive also been trying to listen to some HF stuff and people are throwing around all these abbreviations and i can barely keep up. like QSL, QTH, QRM, QSB... i get that QSL is like a confirmation card thing but people also say it during a QSO to mean they understood? and whats the difference between QRM and QRN because i see both and i thought they were the same thing. also sometimes people just say 73 and sign off and i know thats goodbye but where did that even come from, is it a Q code too or something different entirely. i tried googling it and got a bunch of different pages that all say slightly different things so i figured id just ask here. theres also QRP which i see a lot on this forum, is that just low power operating or is it more specific than that

okay so the Q codes go back way before ham radio, they were originally used by maritime telegraph operators so everyone could communicate fast regardless of what language they spoke. QSL does double duty yeah — the card is named after the code, but on air when someone says QSL it just means acknowledged or i confirm. QRM is interference from other stations, like someone else transmitting nearby and mucking up your signal. QRN is natural static, like lightning crashes and atmospheric noise. so QRM is man made, QRN is nature doing it. easy way to remember it.

73 is not a Q code, its from an old telegraph brevity code called the Phillips Code or sometimes the 92 code depending on who you ask, and 73 just meant best regards. nobody really agrees on the exact history but it stuck around and now its basically universal in ham radio. and yeah QRP is specifically low power, the formal definition is 5 watts or less on HF, though people use it loosely sometimes to just mean running lower power than usual.

one thing that tripped me up when i was new was that some of these get used as questions and answers depending on how you say them, like QRN? means is there static, but just saying QRN means there IS static. same with a lot of them. took me a while to figure out context matters a lot. also youll hear QSY which just means changing frequency, and QRZ which is who is calling me. that one gets used at the start of a pileup a lot and it confused me for the longest time because it sounds like it should mean something more complicated