Ya, that's interesting, I see the loss tangent of (distilled) water (0.005) is not as good as polystyrene (0.0001), but it's not terrible. Now, what can be done with that? ;-) Mikek
Water is diamagnetic; capacitive effects aside, it should decrease the inductance of a solenoid. Distilled or deionized water ought not to be very lossy (though it does warm in a microwave oven).
To keep the experiment simple, I used about 10 or 20 turns on one of those small water bottles. When empty, I measured the self-resonant frequency with a grid dip meter. Filled the bottle with tap water and checked it again. I don't remember the exact frequency but it was definitely in the MHz region. There was change in self-resonant frequency that I was going use to check water level when my project was finished.
John
microwaves operate on a resonant frequency of water. at other frequencies losses should be less.
That's capacitance change. Some rockets had guidance systems that used water-based capacitance change inclinometers:
Not so. Molecular resonances of water are in the IR, a factor of 10^13 / 10^9 = 10,000 higher.
The first microwave ovens ran at 915 MHz, and the large commercial ovens still do. The problem with 915 MHz is that one cannot cook bacon
- too thin.
.The frequencies are chosen to fall fall into the ISM bands: ..
The bands of ISM are harmonically related, so all harmonics of a crude transmitter will fall into one or another of the ISM bands, and not interfere with communications.
Joe Gwinn
Correct. As I say above, "while it actually increases the stray capacitance".
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