Ron:

My ACK ELT antenna in my Nimbus 3 is installed lengthwise, in line with the
fuselage, under the instrument panel (glare shield) cover. I used plastic
tie wraps to secure it to the panel cover. By all reports it puts out a
good signal. My transponder antenna is a 2.5" stubby located vertically on
the fuselage aft of the turtle deck with a 10" aluminum pie plate ( from
the supermarket!) inside the fuselage surrounding the base of the
antenna ATC says it also puts out a decent signal.

Roy B.