James M. Knox wrote:
Darrel Toepfer wrote:

Are you using the included antenna or an external one?

I'm using the included antenna still. There is no doubt that a dual
(high-low) antenna would be a big help. However, I often see the threat
aircraft pass directly in front of my plane and nothing from the ATD
until it is well past. The ATD antenna had a clear view - so I suspect
the problem is more with shadowing of the transmitting antenna.
Unfortunately, there is nothing that can be done about this on the ATD-
equipped aircraft.

But did they have a working transponder? g

Thanks for the reply...