Hi Russ,
That's an interesting idea to use a parabolic to get above the insect
noise. I had problems with crickets last Fall (well, until water got in my
microphone and ended my recording season early...) Based on your
description, I'm guessing you're planning to use something like the Edmund
Optics large parabolic reflectors? I built a microphone using a 18" dish
last summer. I ended up using electrical conduit to fashion a handle, and
then used a thin half inch wide strip of aluminum secured to the conduit to
mount the microphone at the focal point. It worked well enough but I found
it kind of bulky to carry around in the woods (and people gave me some
strange looks!). You've definitely got me interested in trying it out on
the roof this Fall.
I mounted my microphone capsules facing down towards the dish. I wonder if
a small plastic plate covering the backs of the microphones could shed
water into the dish, which could be left with the center hole open so that
it just funnels away? I've seen some parabolic designs that use a largish
center plate (e.g. https://avesrares.wordpress.com/2016/04/28/diy-parabola/=
).
I'm not sure what affect that would have on the sensitivity of the mic.
I was in a bit of a rush to get things ready for Spring migration and
didn't do any experiments with the microphone prior to putting it up other
than basic checks that it worked. Now that it is off the house again it
would be worthwhile seeing how much signal I lose by using the plastic
covering. I'd also like to experiment with number and type of microphone
capsules if I find time.
I've only started going through my recordings from this Spring. I
definitely found some birds this time around, I think Savannah Sparrows
based on the spectrograph. That is better than my previous two attempts.
Good luck!
Dan
p.s. I had no idea a deer made noises like that!
On Thu, Jun 15, 2017 at 7:11 AM, 'Russ Wigh'
[naturerecordists] <> wrote:
>
>
> Thanks Dan
>
>
>
> I have printed your description and the scheme to which you linked. Our
> fall season is fairly dry, and my installation would not be permanent. I
> am told the focal point of this reflector is 6 inches. From there I
> envisioned a protective enclosure of the mic capsule which would allow fo=
r
> a high point in the center of the parabola allowing rain to roll off the
> windscreen fabric. One thing that came to my mind was a whisk with the
> handle cut off and the ends secured into a PVC fitting. That is probably
> way too elaborate, but I have thought about the rain issue. The position =
of
> the contraption on the dormer roof allows me to run one 5 meter cable
> through a window to a shelf where the preamp and recorder sit, and can be
> put on a timer.
>
>
>
> Last year I pushed a Sennheiser ME67 through the dormer window and got
> distant calls, some of which I was able to identify spectrographically.
> But fall on the Georgia coast is still warm, and the cicadas are in full
> voice. I hope to reach past them with the narrow cone of the reflector.
> To avoid insects one morning, about 4:00A.M., I was in a nearby field wit=
h
> the microphone on a lighting stand about 13 ft high. It was pitch dark,
> and out of a grove of wood came a sound I had never heard before.
> https://soundcloud.com/russ-wigh/deer-blowing Scared the hell out of
> me. So much for that effort.
>
>
>
> I noticed a couple of years ago on OldBird=92s website that he used kitch=
en
> wrap to protect his mic. You mentioned it in your response as well.
> Doesn=92t that impair the microphone to some degree? Thanks for your
> response.
>
>
>
> Russ Wigh
>
>
>
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