Conical reflector sources?

["werainey" werainey]

We're interested in testing a conical reflector for long term logging of ba=
t acoustic activity
(frequency range roughly 4-100 kHz).  It seems that mounting the microphone=
 in a shallow
shroud with a drip edge facing vertically downward over a coaxial 22.5 degr=
ee cone (apex up)
would overcome some of the icing and other inclement weather problems we've=
 encountered
with simpler planar reflectors in past years.

Assuming this seems plausible, I'd welcome suggestions for an affordable so=
urce of smooth,
sharply pointed, closed cones of relatively tough, lightweight, weather res=
istant material
(spun sheet aluminum, polycarbonate?). Web searching typical leads to cones=
 with a aperture
at the apex which we don't want.

Bill R.