oryoki2000 wrote:
> Minidisc users who are happy changing discs every 80 minutes need
> read no further...
>
> Hitachi recently confirmed plans to release a 4GB microdrive in
> November. Anticipating price reductions by its Compactflash
> competitors, Hitachi is setting the list price for the 4GB drive at
> $500.
>
> The 4GB microdrive is a good match with Marantz's PMD-670 recorder
> (~$600), which has a Type 2 Compactflash slot and FAT32 file system.=20
> 4GB of storage means the PMD-670 can record DAT-quality uncompressed
> stereo for six hours. If MP2 compression is OK, then you could
> capture more than 24 hours of stereo non-stop.
This business of just shotgunning recording is not my style. I'm not a
fan of listening to long sections of useless recording, and I do listen
to all I record. So, I concentrate on shorter recordings that are
actually what I want. All part of the fieldcraft of recording. I
consider the record buffer to be more important than huge recording lengths=
.
You might want to also think about how you will handle a 4 GB soundfile,
archive it and so on. Look at just how long it will take to just open
the file and such like.
> A field-ready portable power source (including battery, fuse in
> circuit, voltage regulator, power cord, recharger and carrying case)
> costs $90 to $125 from commercial sources.
>
> Astronomy hobbyists use a setup like this to power a telescope's
> equatorial drive in the field. I saw several astronomy sites that
> explain how to build your own field battery setup.=20
The equatorial drive on my big Celestron runs on one 9 volt battery. For
days. A well balanced equatorial drive takes almost no power to run it.
However what does eat power is keeping condensation off the glass
surfaces. Since they are pointed at the cold of space they get
condensation on them, often before anything else. This is generally
taken care of using heat bands around each lens. The heat has to be
quite low so as not to cause undue air movement and spoil the
resolution, but it's still significant. It's all this resistance heat
that needs the battery power. And in many modern setup a big battery is
necessary to keep the laptop computer that's probably taking the photos
going. Also the new Go To scopes have a onboard computer and motor
drives on both axis. Those eat a bit of power, especially if you do a
lot of jumping around the sky with them.
My Celestron is one of the older Ultima scopes. A real nice photography
scope it's equipped with a autoguider (for long exposure photography)
and digital setting circles, but no go to computer. I still do it the
hard way mostly by starhopping. And I still shoot film. About all this
hobby of mine has in common with my frog recording is that both are done
at night. The unwanted man made pollution in astronomy is light. A even
more pervasive problem than sound.
I have a nice Kendrick battery pack like described. It runs the dew
removers, the autoguider. I also use it to power a cigarette lighter
spotlight when not doing astronomy, which it can do for a good part of
the night. It's got a nice shoulder pac, inside of which is a sealed
motorcycle battery. About like carrying the old Nagra, which has been
described as a cement block on a strap. In 10 years I've had to replace
the battery once. There are also gel cell lead acid batteries in this
size range for the truly wild trips through the woods.
Walt
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