To add to the controversy if you want to fly in Canada you might need “diversity,” I.e. both a top and a bottom transponder antenna, in addition to the adsb.
Some people say that having just the bottom antenna might be good enough, and you might not need the top antenna, because it is almost as good. I do not know what to believe.
I would get the skyBeacon (978) for $1859 to be USA compliant by 2020, then in a couple of years when Canada figures out what they might do, upgrade to the 1090 and install your second antenna if needed.
If you buy the new transponder now, can it accept a second transponder antenna?
There is even a chance that Canada might accept the 978 as 455 Bravo Uniform has stated. But I am unsure about that as well.
The skyBeacon cost is $1859, plus 1/2 hour of A&P shop time ($50) to install and $180 for the 337 form to be filled out. Moreover, there is no down (shop) time for the plane during the install and u can get your $500 dollar faa rebate check back, if eligible. Plus a real faa approved, red led navigation light and a led strobe light on your wing.
From the AOPA:
“AOPA’s senior director of airspace, air traffic, and aviation security, has been following the process closely. “The requirements are not 100 percent as [Nav Canada officials] are still finalizing their report, which then must go to Transport Canada for rulemaking,” he said. “We probably will see something official this fall.”
“Nav Canada is requiring a minimum transmit power of 125 watts, which matches the U.S. requirement,” he said. Canada originally said it was going to require diversity—meaning a transponder antenna on top of the airplane, as well as on the bottom, to facilitate reception by the Aireon satellites high overhead—but it is conducting further testing on the diversity requirement based on user feedback”
Mike