At 08:25 PM 12/10/2006, you wrote:
>Hi Marty and Bernie
>
>Thanks for the posts about recording plants, it sounds fascinating! I
snip!
>observe behavior of creepers if they have some other counter
>evolutionary behaviors.
>
>Meena
HI Meena! Long time no talk. I had very similar intentions when I built the
device around 1971. I hoped to hear wood boring beetle adults chewing their
way out of the tree. I expected them to stop at the slightest sound from a
woodpecker, jacking its way up the tree. But as it was located remotely at
another house, I never spent the time needed to capture these events. Never
heard any chewing, but that might have been because the tree was
pest-free. More questions than answers, a real half-done study, but the
equipment worked very well.
I will try to find and photograph my apparatus. Since I never throw away
anything I know exactly where it is; unfortunately it is likely burried
under all the rest of the stuff I also never threw away. It seems to
antiquated--to have an actual CABLE running from tree to house, in this
world of WIFI digital networks.
Bernie's would be much simpler to arrange - all you have to do is bore a
hole in the tree big enough for the hydrophone to fit snugly. Hydrophone
obviously already come water-proofed. :^)
In the case of my tests, the tree did not belong to me, so all I wanted to
do was put a few screws which were later easily removed.
The question of stereo came up at the time, but I had just been working for
the summer for Roger Payne and the only Belden cable I had was a single
conductor and a shield, left over from getting him off to Argentina and the
Right Whales. The only amplifier I had then was mono, too. I wondered if
the brass screw, on which the "needle" rested, would even move
orthogonally, and if it did, would it move the needle orthogonally to
produce a stereo effect. Never tried to answer these. It seems logical
that a bird passing up the tree to the left side would vibrate the screw
differently from a bird on the right, and you might hear the movement, so
it might be worth setting up a stereo, as your sense of place might tell
you quite a lot more about what is happening inside the tree as well.
The emitter follower is pretty standard way of reducing impedance actively,
and so making the line more noise free. It would work with any
piezoelectric device, either with a ceramic cartridge or a hydrophone. I
had set up about a hundred Sona-buoys for Roger previously for listening to
the Capo San Lucas waters remotely from his cliff-top lab, and they all had
emitter followers added for that purpose. The FET is at the mic, and its DC
power flows through the audio line. The load resistor is in the lab. Of
course Sona-buoys in their original application are surrounded by salt
water, so there never is an electrical noise problem.
-- best regards, Marty Michener
MIST Software Assoc. Inc., P. O. Box 269, Hollis, NH 03049
http://www.enjoybirds.com/
If you think plants are not important for living, try it without oxygen for
a few hours.
"I am strongly induced to believe that as in music, the person who
understands every note, if
he also possesses a proper taste, more thoroughly enjoy the whole, so he
who examines each
part of a fine view, may also thoroughly comprehend the full and combined
effect.
Hence, a traveler should be a botanist, for in all views plants form the
chief embellishment."
Charles Darwin, The Voyage of the Beagle
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