Had a brief QSO with W5LFL on my 2M rig with a homebrew, handheld antenna in 1973. This was before home computers and orbital path software so I had to research when, approximately, the shuttle would appear above the horizon with its azimuth and elevation, all well ahead of the actual event. It took several attempts before I could even hear him. I had a buddy manipulating the antenna so he had to track an invisible point in the sky while estimating elevation and azimuth. By sheer luck, we did finally hear him and which point I starting making calls. We only had seconds to make a contact with thousands of people trying to do the same. By some miracle, I was heard and he acknowledged my call sign just before we lost him. Eventually, I received a QSL card from him, acknowledging our (brief) "conversation". Still have that framed in my shack.
"SK" is a morse code prosign meaning "silent key," indicating the last transmission from a station. In this context, "SK" indicates that the operator has died, so the edited title reads a little like "Owen Garriott, W5LFL, deceased, has died."
"SK" meaning Silent Key is not a Morse prosign, it is an initialism as you might use anywhere else in English. The individual letters "S" and "K" are sent separately just like any other word:
••• —•— or di-di-dit (pause) dah-di-dah
There is a prosign <SK> but it has a different meaning - "end of transmission" - and it is sent like this:
•••—•— or di-di-di-dah-di-dah
A prosign is sent as if it were a single letter, without the pauses you would use between letters.
As you might guess, the same prosign could be spelled multiple ways. For example, a prosign named <VA> would be indistinguishable from <SK>, because VA as separate letters would be sent like this:
•••— •— or di-di-di-dah (pause) di-dah
If you take out the pause you have the exact same thing as <SK> above.
Prosigns are customarily typeset with a solid bar over all the letters to indicate they are sent with no pauses as if it were a single letter. When that isn't possible, a prosign may be spelled with angle brackets around it or a similar indication.
This may be a subtle distinction, but in the old days it could save your life. If you ever had to send <SOS> in Morse, trained operators would recognize it faster if you sent it correctly as a prosign:
•••———••• or di-di-di-dah-dah-dah-di-di-dit
instead of sending it incorrectly as individual letters:
••• ——— ••• or di-di-dit (pause) dah-dah-dah (pause) di-di-dit
Here is a chart of Morse code characters and prosigns:
The Technician level license (Essentially it's all amateur frequencies above ~50Mhz, you do get some morse-code on a few lower bands, but they're hardly used by Techs) is very simple to get; there's a lot of "Ham Cram" classes, this is how I got mine. Essentially you study all morning interspersed with a quick primer on Ohms law, common-sense rules and regulations, etc...
There has been a proposed enhancement to the Tech level to give them some lower frequency privileges that's causing a rift in the hobby since the new comers welcome it and the old-timers think it'll kill the hobby* and turn everything into CB radio.
* Common amongst the old timers is that EVERYTHING that isn't morse code (CW) is killing the hobby.
There are many ways to go about getting your license, but if you decide you want to go the self-study route, I highly recommend using https://www.hamradiolicenseexam.com/. I used this tool for a few months before taking my exam at MIT. Also, it's worth studying for the higher class licenses - when I took my exam, the instructor offered and encouraged everyone to take the exam for the higher class for free immediately after.
In addition to having the question pools available and giving practice tests it also has user-contributed explanations of how to arrive at the correct answer for each question which I find very helpful.
I'd also highly recommend the Gordon West ham radio study books, they do an excellent job of teaching you both the answer, and the theory behind the answer.
1. Read through (and understand) West's book.
2. Go to qrz.com and take the practice tests until I could pass with a 95% multiple times in a row, and I had answered every question in the test database correctly at least once. You only need 85% to pass the real exam but I wanted a margin of error.
I passed my tech, general, and extra exams on my first tries. That's the most prepared I've been for a test in decades.
Current requirement is lower. Only 74% (26/35 or 37/50) to pass.
One other thing to know is that the exam questions are split in to sections (35 sections for Tech/General, 50 for Extra) and only one question from each section is selected. This means that you don't need to worry about getting multiple questions from sections you struggle with and dragging down your score.
The FCC have a commercial partnership with Best Copy & Print Inc, who can manually search through the FCC archives on your behalf to retrieve and duplicate old licensing documents. A fee is charged for this service, but it's quite reasonable.
