JFYI: 2 solid 1/4 lambda counterpoises made from a tape-measure material have solved the problem of transmitting at 5W with Baofeng DM-1801 standard antenna and raspberry pi.
photo_2021-09-22_21-51-43.jpg (69.61 KiB) Viewed 5338 times
photo_2021-09-22_21-51-42.jpg (64.54 KiB) Viewed 5338 times