One of my favorite portable or "field" HF antennas is the "sloper." The sloper is often used because it requires only 1 tall support to work well.
In this video from Tim (G5TM), we see both the "positives" and "negatives" of this popular antenna.
If you can't see the video please insert this title URL into your browser search box: https://www.youtube.com/watch?v=Z7gD6_sHpVI
Here are some comments from Tim (G5TM):