How to Slinky Antenna.
Radio amateurs (hams) have used almost any metal object as an HF antenna.
In this video, Bobby (W6IWN) uses the common childhood toy called a slinky to make contacts in France.
Depending on how far you stretch the "slinky", you will get a HF helix capable of tuning several bands.
Coupled with a qrp rig, such as the Xiegu G-90 transceiver, you'll have a basic SOTA/POTA station antenna which can be easily transported and stored for future use.
If you can't see the video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=IFKAcCREPHs
Here are some comments from Bobby (W6IWN):
W6IWN SOTA & HAM RADIO