[757labs] unused farmland?
trevorl.salad at gmail.com
Wed Dec 21 08:56:48 EST 2011
A very simple estes style rocket could be used to detect the proper
conditions. Looks like lightning is very noticeable in the AM band.
Make a very small shielded AM transmitter on a fixed frequency, and a
very small shielded AM receiver set to the same frequency. Obviously
both are small enough to fit inside the rocket. Determine and record
the level of interference at ground between reciever and transmitter.
Launch the rocket and keep calculating that difference through the
entire trip. The greater the recorded interference, the larger the
That alone would be a pretty nifty hack...
The cap sounds expensive, no two ways about it.
The launch wire sounds expensive too. What about using something like
normal kite twine doped with graphite?
On 12/20/11, Scott Dorsey <kludge at panix.com> wrote:
> Standard way to get that kind of breakdown voltage is with stacked glass
> or teflon sheets. Plating or sputtering them gives you a little better
> performance than sandwiching foil, but not by very much.
> Problem is the thicker you make the dielectric, the higher the breakdown
> voltage but the lower the capacitance. You can derive the capacitance
> from first principles using Coulomb's Law or you can look in the ITT
> for both the chart of breakdown voltages and dielectric constants for
> various materials and the capacitance equation.
> Vacuum and air are good for capacitance, not so good for breakdown voltage.
> Glass is good for breakdown voltage, not so great for capacitance. Plastics
> are mostly in-between. Old storm windows are usually available for the
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> If we knew what we were doing it wouldn't be research.
Failure is just success rounded down. - T-Rex
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