An antenna that performs on multiple bands will often be a compromise and will perform differently on each band depending on length of antenna and resonance.

Better performance can be achieved on a mono-band antenna, and could also still be resonant on other frequencies.

http://udel.edu/~mm/ham/randomWire/

Southwire or Cerro Vinylon THHN wire

End-Fed Half-Wave. Uses 9:1 UNUN to bring resistance down to an acceptable tunable level.

Reception can improve with counterpoises.

EARCHI Antenna, HyEndFed, MyAntennas

• https://www.reddit.com/r/amateurradio/comments/3nrtcc/earchi_end_fed_antenna_doesnt_work/
• https://www.reddit.com/r/amateurradio/comments/5uz35e/testing_my_field_portable_30_vertical/
• https://www.reddit.com/r/amateurradio/comments/6c148d/ferrite_chokes_on_feedline/
• https://www.nonstopsystems.com/radio/pdf-ant/antenna-article-endfed-earch-cqar.pdf
• https://www.reddit.com/r/amateurradio/comments/7uwa5y/endfed_matchbox_antenna_woes/
• https://www.reddit.com/r/amateurradio/comments/9x23g7/earchi_end_fed_antenna_with_a_little_matchbox_91/
• https://www.reddit.com/r/amateurradio/comments/7mpfvb/end_fed_half_wave_wires_whats_the_difference/
• https://www.reddit.com/r/amateurradio/comments/24rs81/earchi_endfed_rf_issues/
• https://www.reddit.com/r/amateurradio/comments/bu1rqe/91_matchbox_and_counterpoise/

Antenna layout styles, sloper, inverted vee.

Also reference the often counter-argued sidekick - ZS6BKW - https://www.w5ddl.org/files/Zs6bkw_vs_G5rv_20100221b.pdf

Great for attics. Resists noise.