Xref: utzoo rec.autos:15569 sci.electronics:5221 misc.consumers:8805
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ncar!noao!asuvax!anasaz!john
From: john@anasaz.UUCP (John Moore)
Newsgroups: rec.autos,sci.electronics,misc.consumers
Subject: Re: Radar Detectors (Ka band)
Keywords: radar, cops, Ka, X, K
Message-ID: <1580@anasaz.UUCP>
Date: 17 Feb 89 14:24:32 GMT
References: <603@icus.islp.ny.us> <7944@netnews.upenn.edu> <249@turbo.RAY.COM>
Reply-To: john@anasaz.UUCP (John Moore)
Organization: Anasazi Inc, Phoenix AZ
Lines: 39

In article <249@turbo.RAY.COM> kenneth@pebbles.ray.com writes:
]In article <7944@netnews.upenn.edu>, depolo@eniac.seas.upenn.edu (Jeff DePolo) writes:
]> The Ka detectors (currently only made by Bel) are
]> somewhat worthless for a number of reasons.  First of all, the design
]> of the photo radar unit makes it very difficult to detect.  The beam
]> that the radar uses is very narrow, and is angled in such a way that it
]> does not transmit down a lane of traffic, rather, at an angle across it.
]
]At an angle? What about cosine error? (Or do I have the angle backwards?)
]

The angle is known to the onboard computer which simply compensates.

]enough warning to at least slow down......one of the few good things about
]this state (MA) is that most cars don't have front plates, and even if they
]did, the RMV won't tell the other state who you are anyway. (Not part of
]the DLC).

The system here in Paradise Valley has a slave stobe and camera
mounted on a tripod about 50 feet behind the main unit. The slave
takes a picture of the rear plate.

Even nastier, the cameras work with infrared strobes and film
and are run at night, when it is much harder to spot the vehicle
holding the radar.

However, for some bizarre reason, the town decided (no doubt
the politicos on the town council) to put up a yellow warning
sign ("warning - photo radar in use") with the mobile
unit. This sign is normally somewhat concealed, smaller than
a normal warning sign, mounted at ground level, and right
next to the truck. In other words, if you can see the sign,
you have already seen the truck!

-- 
John Moore (NJ7E)           mcdphx!anasaz!john asuvax!anasaz!john
(602) 861-7607 (day or eve) 
The opinions expressed here are obviously not mine, so they must be
someone else's. :-)