----- Original Message ----- From: "Peter L. Peres" Subject: Re: [EE]: 10GHz and fluorescent light > In the light of Alan B. Pearce's posting with PIN modulators the > flurescent light 'jammer' (with spiral around it) makes a lot of sense. Having a tuned waveguide just means that more energy gets a better match into and out of the modulator. > the fluorescent is driven with just the right frequency and the spiral is > tuned to the radar frequency it will become a AM modulated reflector. The spiral around the fluorescent tube hopes to exploit a negative resistance effect of the plasma. If the spiral and plasma are just right, plasma-maser instability or negative resistance means a bigger signal is re-radiated than is incident! But if you get it wrong, Landau damping absorbs incident energy and you get a hotter plasma. In effect, the plasma is an active transducer. The stream of current in the spiral tuned waveguide is like an air current across a read and tuned pipe - a whistle. > radar will be looking for doppler but maybe supermassive AM of the return > wave will cause it to produce that pseudo doppler harmonic in the radar > gun itself (either by intermodulation in the detector or by overriding the > FM limiter channel with too strong AM). Perhaps 'swamp' rather than 'supermassive' is a better term, and pseudo Doppler harmonic? And I've never heard of 'Doppler harmonics', but a hard-limited, FM limited, AM modulated signal would appear to be an FM signal, because the jittering edges of the signal would still contain the AM sidebands. The clipping would just create high-order harmonics. And a PLL detector will just lock on to the 'loudest' signal. Sorry about that stuff about repeat-back jamming which is useful in other contexts. Simple, (non pulsed or chirped) Doppler radar doesn't need it. > Hmm. Is it still legal if we know > how it works or does it have to be snake oil to be legal and work ? Or > some other combination ... What? ******************************************************* Is the American Identity freedom to pursue happiness and profit from the fruit of your own labors, or a servant leased to corporations by federal government that taxes you to your tolerance? ******************************************************* -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics