Would it be wonderful to have a small HF antenna on your roof or balcony? Yes, but almost every design e.g. EH antenna, or Isotron, Miracle Whip or helical antennas, they perform -10 or -12 dB less than a full dipole. How bad is it? I think in use with digimodes like JT65A and WSPR the software compensate the losses of the antenna. (Ahhh, don't shoot the sheriff) Click on the photo to start the video. More info in English can be found here.