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Keep an eye on this one. Undetectable Radar! The inventor says it sounds like static on a receiver.
http://tinyurl.com/nf7aq BTW: It is an interesting end to the URL the TinyURL generated for this link. _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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----- Original Message -----
From: "Mark Saunders, KJ7BS" <[hidden email]> To: "Elecraft Mail List" <[hidden email]>; "QRP-L Mail List" <[hidden email]> Sent: Tuesday, June 27, 2006 4:16 PM Subject: [QRP-L] Undetectable Radar > Keep an eye on this one. Undetectable Radar! The inventor says it sounds > like static on a receiver. > > http://tinyurl.com/nf7aq It doesn't look much different from a standard spread-spectrum signal. They aren't exactly undetectable, the IRA could tell when the British army were in the vicinity and using SS signals because they could hear the increased noise level on the scanners they used to monitor the military radio channels. Leon ______________________________________________________________ QRP-L mailing list Home: http://mailman.qth.net/mailman/listinfo/qrp-l Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] |
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In reply to this post by Mark, KJ7BS
Mike, in radar as in QRP, there is no free lunch.
Rest assured any broad spectrum signal can be found. For one thing it inevitably brings up the noise floor and that can be detected. Good receivers like the K2, could be helpful in noting such effects from new radars or BPL use in an area. Spreading your signal out over many frequencies with a noise like character, your radar then suffers from lack of coherency, and thus your range will be affected, and perhaps its discrimination of the size of objects. However, there are systems being studied that look at the effect on the spectrum of objects moving thru. (like the flutter on your TV signal when a plane flies over) That passive sort of radar has much to offer. There is no emanation from the site of the radar receiver, and thus the target generates the only signal. A couple of receivers provide the ranging by comparing delays in signals effects. Again range suffers, and you have to have a super quiet receiver to extend range. No free lunch, but the trade offs are attractive from the stealth angle. Stuart K5KVH _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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