I know the 9900BX is and active TCAD, meaning that it Pings the Transponders in your area. I don't know how or which antenna the Pinging is transmitted? Anyone know? How often? and with a Freq. and strength that may interfere with the WSI?

 

I have lots of things in the back that could cause problems and is the reason I tried the antenna under the glareshield in the first place. AP servos, Transmit antennas, AC. But Why it has a BER of "0" on the ground between hangars and then it is worse in the air is confusing. I only know of the 69 lb steel landing gear that goes back there in the air that is a major change form on the ground.

 

I'm also told that the Marine antenna does NOT need a ground plane so it doesn't need to be on the antenna tray.

 

Thanks,