OT:
John - Spring Peepers started here (mid-Hudson Valley, NY) in earnest last
night.
Woodcocks have been doing their thing for a month or more.
On Tue, Mar 13, 2012 at 10:13 AM, John Crockett <> wrote:
> **
>
>
> Hi Peter
>
> Here is a link that shows how to wire a battery box using one 9v battery
> for two channels.
>
> Description:
> http://www.megalithia.com/elect/battbox.html
>
> Schematic:
> http://www.megalithia.com/elect/BATTBOX.pdf
>
> You can simplify this by eliminating the extra output that has a 300hz
> high pass filter.
>
> I am measuring 4.3v across two EM172 capsules and 4.9v across one capsule
> using this box and a not-very-fresh 9v battery (battery unloaded is only
> delivering 8.9 v, so a fresh battery would be even higher). Powering all
> four capsules will be slightly lower than this, but well within the 3-10 =
v
> spec for these capsules.
>
> I am in the process of building the same array, with only two capsules. I
> just need a good shielded cable and I'll be ready to catch the spring
> peeper chorus, which normally doesn't arrive until early April but may be
> very early this year, as everything else is. It's been a warm winter and
> very early spring, distressingly so.
>
> John
>
> John L. Crockett
> Wesminster, Vermont
>
>
> --- In Peter Shute <> wrote:
> >
> > Thanks for that. Does the change of resistor value change the
> recommended capacitor value?
> >
> > And is there any way to use a single 9V battery for both channels?
> >
> > Peter Shute
> >
> > > From: [mailto:
> On Behalf Of Brian Dasilva
> > > Sent: Tuesday, 13 March 2012 8:52 AM
> > >
> > > 9V battery Thru 9K ohms....
> >
|