#24
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This conversation which started in nonsense, isn't getting any closer to sense.
All this concern about "transmitter vlf" (title of the thread) with almost no concern about the receiver. Ordinary metal detectors have VLF transmitters which are designed by real engineers to actually transmit! Not this NE555 or calculator-on-a-stick malarkey. And, real metal detectors have real receivers. That really work. The most sensitive units can detect a VLF energy perturbation about the same magnitude as the energy of one red wavelength photon. You heard me right. Multiply voltage sensitivity by the equivalent current sensitivity and by the response time, and if you have the necessary scientific and engineering knowledge, you can verify it for yourself. One red photon. Try that with your swivelly thingy. Holding it in your hand in a perfectly neutral (laboratory perfect, non-field) environment, its directional sensitivity is limited by hand tremor, as any time spent following dowsing forum posts will confirm. It ain't the rod, it's the hand holding it and therefore the brain that's behind the hand. Anyone who's dealt with the challenge of making sensitive electronic measurements where something in the signal path had to be hand-held knows the problem: until you eliminate the ability of the hand to change the signal, you're schitt outa luck. It ain't happnin'. Hand tremor has too much energy. I am not saying that dowsing is entirely bogus. What I am saying is that the electrical theories behind LRL'ing are entirely bogus, and provably so. In fact it's that provability that has LRL fans so parsed arf with folks like Carl and the A.R. and even with me. In the case of Carl and myself, VLF electronics are our livelihood, for which we get paid only because the stuff we design actually works and nobody, not even the LRL dependabillies, dispute that it works! In the VLF detection industry there are lots of arguments about who's got the best stuff for what purpose and whose advertising department stretches the truth a hair too much, but assertions that the stuff is bogus from the get-go are entirely absent no matter how stiff the competition. To simplify the foregoing argument a bit: no matter how much I dislike a competitor in the metal detection business, I can't say that metal detection is all a fraud. However I can say that all LRL's are fraudulent, because they are not competing for targets to be located, they don't locate buried targets at all! They only do wallet biopsies. --Dave J. |
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