* https://en.wikipedia.org/wiki/Random_wire_antenna
There are also commercially available products that are fairly portable and probably give you a better SWR; e.g.:
* https://www.youtube.com/results?search_query=Buddipole
From one of the photos, seems like the author is using an Elecraft KX-2, which is really a clever bit of kit that packs a big bunch in small package:
* https://elecraft.com/products/kx2-ssb-cw-data-80-10-m-transc...
The receiver is very sensitive and the filter can be adjusted to clamp down on one signal. I do CW most of the time so I can setup and make contacts in a lot of noisy, challenging places, from Grants Tomb in NYC to a little POTA site just north of KC airport with power distribution lines high overhead, I've been able to work coast to coast with either an end-fed halfwave or a Chelegance MC750 vertical. (Far easier and less bulky than my Buddipole or Buddistick). I also have an end-fed random wire for use with my KX2. I took it to Old Town San Diego and was able to band-hop while a friend was on 20m at the same picnic table. With the random wire I was still able to pull in Italy on 5W!
I'm headed for Madison, WI tomorrow and will be playing radio in the evenings weather (and solar storm) dependent.