The folks at Cornell University have done a substantial amount of work
recording elephants, and have put a lot of information about their
recordings on the web. Google on 'Cornell record elephant' and you'll
find them.
They have used and recommend Earthworks QTC-1 mikes into a Sound
Devices MP-2 preamplifier and then into a recorder at line level.
That's a bit beyond your budget, but a good reference point.
You can contact them at: info"at"elephantlisteningproject.org
(substitute @ for "at")
They've done interesting things earlier in the decade with little home-
brew Windows computers powered by a marine battery called "autonomous
record units", but these days many of the smaller digital recorders
could handle the recording chore if driven at line level as noted by
previous posters.
When trying to record deep into the infrasound, bear in mind that
you'll need effective shockmounting to avoid structure-borne vibration
and windscreening to avoid even the slightest turbulence in the air.
It's definitely best if done with you many feet from the microphone!
|