Current bugbears

Shawn Rutledge shawn.t.rutledge at gmail.com
Tue Sep 4 20:03:33 CEST 2007


On 9/4/07, Richi Plana <myopenmoko at richip.dhs.org> wrote:
> Fascinating. So "passive receivers" really aren't? Or are there classes
> of receivers which are (no amplification or very sensitive pickups)?

In theory nowadays DSPs are fast enough to process the lower bands of
radio signals directly off-the-air with no IF, but I'm not sure if
anybody's doing that yet.  Suspect the modern ham HF rigs might be
doing that, but haven't researched it.  But a clock signal for any
digital system might also cause radiated interference, right?  Radar
and GPS and GSM are all too high in frequency to handle that way, so
far.

> Prolly off-topic, but I sure am curious. Are there no radar detectors
> which don't give off their presence?

http://en.wikipedia.org/wiki/Radar_detector says that first radar
detector detector detectors were developed so the radar detector can
shut down when it detects that it's being detected; then they just
started using a lot of different IF's so the police can't monitor them
all.  So modern radar detectors are mostly immune to detection.

Yes it's off-topic... will shut up now



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