Martin wrote:
The issue is with FCC IIRC. I vaguely recall that the frequency used by the European version can’t be used in the US
Correct, the ISM frequency used in Europe is not one of the ISM frequencies in the US.
mm_flynn wrote:
I passed on the powerflarm because I hoped to have something ‘installed’ to display on the 530, but the European powerflarm manually says ‘do not install in US aircraft’ which makes it a bit challenging to get an avionics shop to install it anyhow !.
The issue is with FCC IIRC. I vaguely recall that the frequency used by the European version can’t be used in the US. They eventually did a US version but it uses a different frequency. Just as a little side note if someone wants to investigate further.
While the reason for the restriction on installation is the different radio frequency usage (and FCC not FAA issue), my avionics shop took a view that installing something where the instruction manual explicitly forbid the installation wasn’t something they were comfortable doing.
Years later, I have a new bit of info on this mysterious product “which cannot possibly work as described” 
I’ve read an account from one owner, saying that the ATD300 gives you relative altitude, distance estimated by signal strength, and with a “special antenna” it can tell you if the target is in front or behind.
