I did my extra when I was in high school and didn’t use it for decades. I wish I kept up with it throughout the last 20+ years. Trying to re-learn everything now is much harder than I expected it to be.
Regarding the AE: Keep reviewing the questions online. Take the sample tests. After a couple of weeks, you'll be surprised at how much you retain. Remember, the test is designed so that you don't need to be a whiz at EVERY section.
Most of the older cell sites that I think where protected or might have been .Gov rooms had copper wire screen surrounding the entire room along with the door and all the seems over lapped. I know nothing like a Am/Fm radio or my cell phone would work once I passed threw the door and the door was still open behind me, one or two steps in, nothing.
That"s all they had was one thin layer of copper wire screen door looking mesh. Now is that, it I don't know but these SBA sites have the .Gov Eqp on those towers and now have moved there Eqp to there own buildings for there own network use.
If you are worried about this there are a lot of tube transceivers for sale. Get one learn how to use it and use it at least once a week. The Extra exam is difficult but not imposable and once you get through it you will most likely never use most of what you need to know to pass the test. If you have a good memory and if you dedicate 30 minets a day for 30 days doing the practice tests on QRZ.COM you will be ready to pass the exam. I did my first time and only got 3 wrong so it is very doable. I have no radio or electronic background. Look
If you have questions contact me. I will respond with my email and phone number or you can look me up on QRZ my email is listed. I don't know where you live but a group of local hams get togather once a month for lunch. You are welcome to attend if you are in the Springfield MA area just let me know if you will be able to attend the next lunch will be held at Krazy's Jake's on RT.20 Boston Rd. In Wilbraham MA February 26th. at 11:30 am. This invitation is open to any ham that would like to attend just let.me know so I can add you to the reservation. We usually have 15 to 22 attend each month.