Reddit mentions of Portable Antenna Bundle with 7M HF Antenna Spool, SMA Adapter and Telescopic Whip

Seconding the idea that you don't have to spend much to listen. Get a quality receiver that supports SSB and an external antenna like the Tecsun PL-660 for $110, run the included wire antenna across your balcony, and you'll be off to the races listening to broadcasters and hams. For digital modes you should be able to connect the headphone jack to the microphone jack on your computer, although this isn't something I've personally tried.

Alternately, get a quality SDR like the SDRplay RSP1A for $120 and connect a longwire or loop antenna to it. SDRs have advantages over a traditional receiver, and are even more compelling if you're already planing to use your computer for decoding digital modes.

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I'm luck to have space to run a ~100ft longwire outdoors and alternate between listening on the two models I mentioned above. They've both great but I use the RSP1A the most, largely because of how handy the spectrum waterfall display is.