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Comment Brain Waves (Score 1) 123

I'm surprised that no one has mentioned that Brain Waves (eg Beta, Alpha, Theta, Delta) were discovered at the beginning of the 20th century.
Different brain wave frequencies have long been associated with different mental states.

Building Brain Wave Detectors was all the rage amongst hobbyists many years ago.
Brain Waves are normally detected using electrodes on the scalp, but they also generate very weak fields which can be picked up by non-contact methods in a screened room.

Surely this is simply an extension of that research?

Comment Re:Myth? (Score 1) 160

> Antennas are sized and shaped for the specific frequency the radio will be feeding into it. Changing the antenna size to something incompatible can destroy the radio, the radio wave, or both.

Sorry,, but this is completely wrong.

If you just changed to a different frequency dipole, then yes.

But that isn't what was suggested. You can change to a larger antenna which DOS work on the same band, eg a phased array, a yagi, capacitive loaded dipole, or in his example, a dish. The antenna must still be resonant, but have a larger capture-area.

Comment Re:This is a good thing. (Score 3, Insightful) 291

> Here's the problem though; to pay for basic income, everyone has to earn less.

Actually, no.

Up to now the increase profits from automation have gone to the Super Rich. There has been massive transfer of wealth from the poor and middle class.

To fund "basic income", taxation has to be made fairer so that more profits stay with the people.

Probably won't happen in America though. Not till after the mass riots.

Comment Re:Question: Evading Police radar-detector-detecto (Score 1) 42

Totally correct

The cheap radar detectors use a simple Direct Conversion receiver with a primitive diode mixer, so the Local Oscillator is radiated back through the antenna and hence is easily detected.

Adding an RF stage would fix the L.O. radiation, or by changing to a (slightly more complex) Superhet design.

Comment Re:probably, detects superheterodyne stage (Score 1) 42

A simple (well shielded) RF stage is all that's needed to block Local Oscillator radiation from the Antenna.

Plus the choice of IF stage decides what frequency the L.O. will be on, so false detection's will make any "radar detector, detector" pretty much useless.

The existing Radar Detectors rely on consumer grade Radar Detectors being very primitive devices with a passive detector (eg no shielding)

Comment Re:Navigation wqy bqck then (Score 1) 106

There is a routine way to measure Longitude on land which uses some external method the establish the exact time of local noon (eg a lunar eclipse, the transit of Venus, the position of Jupiter's moons), then this information is conveyed (by mail) to the nearest observatory, who can then calculate your position for you.

I recall that this was one of the reasons that astronomers made long voyages to carefully measure the Transit of Venus or Mercury.

https://en.wikipedia.org/wiki/...

Comment Spread Spectrum (Score 1) 142

It is fundamental that a well designed Spread Spectrum transmission is essentially the same as wideband noise, and unless you know the code, is un-crackable.

The Spreading Code itself provides the Encryption (eg via Gold-Codes, or if necessary, via a one-time pad)

The idea of Extra Terrestrial Intelligence using Spread Spectrum is not a new idea. It dates back to the '40's when Spread Spectrum was first declassified.

Comment Re:Don't say that this side of the Pacific... (Score 5, Informative) 75

As always there were many who help develop a given technology.

Many companies marketed ISB band links, but it was Lucent (owned by NCR) who developed the WaveLan system which evolved into the various WiFi standards we have today.

https://en.wikipedia.org/wiki/...

But it was the Australian CSIRO who patented the modulation scheme (FFT with multiple carriers) that was the foundation technology for WiFi.

https://en.wikipedia.org/wiki/...

Comment Re:Nothing special... (Score 1) 80

Wow, nasty much? Along with the half-wit up-votes.

Actually, the OP is correct:

- The term "Axle Assembly" refers to the axle housing as well as as the actual axles.

  - And if it doesn't have axles, how come the wheels don't fall off?

  - And having hub motors adds essentially nothing to it's off-road ability. It could as well use chains, hydraulics, or more conventional shafts and universals.

It's essentially no different to a conventional 4WD, except that the pivot points are above the center of gravity.

Comment Re:RC Rules (Score 1) 110

> I bet you could count on 2 hands the number of people who were hobby flying RC aircraft in your city

Utter rubbish.

When I was a kid (rural Australia, in the 1950's and 60's), RC modeling was a huge hobby. Most of us progressed from Free-Flight, to Control Line models, to RC flying. Not to mention RC boats and cars.

Admittedly the gear was rather basic with only one or two channels. We could only dream of owning the expensive USA gear, hence our homemade Valve (Tube) Transmitters, Receivers, servos, tone decoders, etc.

Surely you've seen the many DIY magazine articles and books from back then?

http://www.singlestickstuff.co...

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