Thanks folks ( Rob , Oryoki and all) for the rapid replies.
My application is to audio record for possible direct electrophonic
and/or electromagnetic emissions from meteors at VLF (very low
frequency). There is a debate in science as to whether or not people can
hear or have actually heard ( or can sense somehow) meteors directly.
Actual scientific proof and documentation are sparse. So I think I will
give it a go.
.
Microphones will not be in play. Rather, I will be using a McGreevy
WR3-e sferic/natural radio type receiver. The challenge with recording
VLF is that the 60 Hz power grid causes buzzing interference so it is
best to be far away from power lines of any sort. I need stereo
recording ability so as to be able to record a second short wave radio
that will be tuned to WWV time signals so that time stamping will be
absolutely precise. Once I have the audio recording then I can analyze
it via spectrograph and compare it to my nightly all-sky video fireball
captures.
:
It seems like all is solvable except for the 8 hour field recording
device. Also, continuous filing without gaps may be an issue...or
perhaps a compromise?
:
Also, battery recharging is no problem as I can plug batteries in at my
house during the daytime. No need for solar panels.
:
Hearing meteors directly ( and auroral phenomena for that matter ) may
be so subtle that it merges with the observer's imagination of the
sound. It would be cool to have some solid data.
Thanks!
Thomas
oryoki2000 wrote:
> Tell us more about the recorder and microphones you plan to use, and
> how you will use the recordings. There are portable recorders that
> can record for 12 hours or more using their internal battery alone.
> (Sony PCM-D50 is one example.)
>
> Assuming you will need an external battery, check your recorder's
> external AC adapter to determine what DC voltage and amperage it
> provides to the recorder. Use this to guide your selection of an
> external battery pack.
>
> A few external battery solutions mentioned here in the past week include
>
> http://www.laptopsforless.com/portable-dvd-battery/pr2e.htm
> http://www.bixnet.com/5v7libapa.html
> http://www.bixnet.com/mumiexbapaki1.html
> http://www.bixnet.com/misihicabapa.html
> http://tinyurl.com/8zjel8 (Amazon.com)
> http://tinyurl.com/96fpmb (Amazon.com)
>
> Here's a forum that talks about battery power solutions for
> long-duration recording
> http://taperssection.com/index.php/board,25.0.html
>
> And here's a fellow that makes custom C and D cell battery sleds with
> the proper electronics and connector to power different recorders.
> These are expensive, but work well.
> http://www.sonicstudios.com/batsys98.htm
>
> --oryoki
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