On Aug 14, 7:01*am, " wrote:
On Aug 14, 7:01*am, (Alan) wrote:

* Well, not really a free frequency. *433 MHz is in the middle of an
amateur radio band. *That frequency is used for various other services
as well, including, I think, the common wireless yard thermometers.

* * * * Alan

In the US, FLARM will operate around 915MHz, with frequency hopping.
This is in one of the 'license free' bands.

Urs
FLARM

433mhz was stated by the folks at Butterfly Aero. Are you saying
they're wrong? Interesting...