Wide-band WebSDR: Control a short-wave receiver over the web

But perhaps I've misunderstood. The crazier antennas are generally down in HF frequencies, below ~30MHz. They're crazier because longer wavelengths put more physical demands on antenna optimization. Making an antenna which efficiently operates a 4MHz chunk of spectrum 144-148MHz means you can build something tuned at 146MHz and only suffer very small performance difference when moving <2% off either side of this range. That's a completely different story to HF freqs, Eg. operating 1.8-5.5MHz is <4MHz of spectrum but that <4MHz chunk represents a 300% increase in frequency moving from lower to upper end, a far cry from the 2% needed before.

So, to summarize, you can definitely and easily start out without any DIY gear, just usin turn-key stuff. Make friends with other amateurs working the higher/easier frequencies. Even in HF, you can still go a long just by draping bits of old wire around the place, there's still a bit of an art to this but not so difficult to learn :)