Interesting find from Italy. What happened to made in USA??
These surely appear
to be a better choice than those poorly made, over rated Antennas Direct POS's from China. The big question is the quality of their materials.
Also, the type of feedpoint. Is it 300 ohm or are they using some attached balun?
According to their
own polar plots, their Sigma6HD ($130) is not just over priced, but a poorer performer than their next step down, the BLU920F for $42 less ($88). But, for $33 less than that the BLU420F ($55) seems to be a better bargain.
Attached are the polar plots, resized for comparison of their best UHF models. Clearly the 920F has the tighter pattern. The disadvantage is it has to be mounted at the top of the mast unlike the others that can be mounted almost anywhere below.
In the following order;
Sigma6HD, BLU920F, BLU420+, BLU420F, LP45F.