TLDR: What hobby-level test equipment would you recommend for a first build project, a 100mW medium wave AM transmitter?
Up until now, I’ve just been a user of radios, but never understood at a fundamental level how the parts worked together. I’ve built crystal receiver kits and arduino-powered robots with the kids, but always following someone else’s instructions. At present, my troubleshooting ability is mostly limited to making sure I followed directions or a schematic correctly and checking for bad connections/solder joints. I look at RF circuits with a DC short, and it blows my mind that it works. But, I’m working on correcting that.
I figure there’s only so much I can learn from reading forum posts and watching YouTube videos. I want to build something, if not from scratch, then at least with an understanding of why the designer chose the components he did. My plan is to build several iterations, starting with something super-simple, like using an op-amp to generate a carrier, and modulate it directly with a line-level audio source. Then I’d like to improve the design step-by-step to get better quality audio, low-pass filtering, and a usable range with a matched antenna.
Aside from the actual components and tools to assemble them, what am I going to need for this journey? I’ve got a breadboard, soldering station, multi-meter, etc. as well as the “end user” stuff like a dummy load and SWR meter, but I don’t expect to need those until much later. I’ve been thinking of getting an old analog oscilloscope on eBay or Craigslist since they seem to be available around $50 if you’re patient. I guess at some point I’ll need to prototype a PCB or order it from China. Can some of you more experienced guys tell me if there’s something important that I’m missing here?
I realize I’m probably not really giving enough information to get a good answer, but I’d at least like to get some ideas on what to start thinking about from those who have done it before.