One on top, one on bottom, I have the more powerful transmitter in the bottom antenna for flight use. The top antenna is certainly flight useable also but by habit I use it for ground operations and monitoring in the air. The top antenna is not subject to blanking by the landing gear on the ground which can happen although very infrequently (like 3 or 4 times in 1000 hrs)
ME/AE '82 Retired.
RV-7A: Flying since April 15, 2012. 980 hrs
YIO-360-M1B, mags, CS, GRT EX Horizons & A/P, Navworx
Unpainted, polished....kinda'... Eyeballin' vinyl really hard.