The auto transponsder units, mentioned early on for an installation of wires across a valley (Canada?) and for other obstacles - where are they made? As anyone else experience of hearing their auto TX msg?
Did you mean Obstacle Collision Avoidance System (OCAS)?
If so, Norway (invented here, but bought by some wind turbine company, might have moved it), and yes I have. "Test flight" of well known span (to the pilot)
Info on the system from the AIP:
https://www.ippc.no/norway_aip/curre...ENR_4_5_en.pdf