The next step was to find a better location for the antenna. I erected it on a pole around 30 meters away from the house, and prepared the necessary RG-58 coax. Still with the 1.5 meter whip, I mounted the enclosure at around 2 meters, so the total height of the antenna is 3.5 meters. Mounting it higher will increase its gain.
Weather permitting, I will erect my 310-degree beverage tomorrow. It will be interesting to compare noise floors and signal levels. I will also replace the 1.5 meter whip with the 3 meter whip to see how much gain increases.
Already at this stage though, the Z1501 has proved to be an excellent all-round antenna, both with regards to coverage (since it is omni-directional) and frequency range.