On our 320 we have 10 antennae, all internal. Eight work perfectly, one doesn't work and one works great most of the time.

 

The one that doesn't seem to work when mounted internally is the StrikeFinder. It hangs from the top of the fuselage behind the baggage bulkhead. It's mounted on the underside of a big aluminum ground plane. The StrikeFinder lights up when there are storms in the area but has no directionality. Hollis Helms mounted his outside on the belly and it works fine.

 

The one that works great MOST of the time is the transponder. It's an AAE mounted on the fuselage side just ahead of the tail. No problem unless we're heading directly toward the radar site. In this circumstance I believe that the firewall blocks the signal and ATC sometimes looses our transponder. A slight turn in either directions will get us back in radar contact. I'm mounting a standard transponder antenna externally on the belly under the passenger seat to solve this problem.

 

Bill Harrelson

N5ZQ 320 1,100 hrs

N6ZQ   IV  3.793%