On Wed, 16 Feb 2011 15:31:52 -0600, Jim Yanik
wrote:

one "calibrator" I've seen was a simple one transistor oscillator,and it
was for checking radar DETECTORS.
at a short range,it would set off X-band detectors.
IIRC,it used a MF914 transistor and stripline PCB. or maybe MF912....

http://blockyourid.com/~gbpprorg/mil/wall/speed/index.html
No RF involved. It generates a tone that modulates the Gunn diode
bias voltage, thus simulating a doppler shift.

You might be thinking of the Highway Zapper Radar Activator.
http://pe2bz.philpem.me.uk/Comm/-%20Transmitters/-%20Jammers/Info-801-PoliceRadarJamming/zapper.html
http://books.google.com/books?id=KrfIjdl-EMwC&pg=PA45&lpg=PA45&dq=highway+zapper+radar+acti vator
It's an X band radar jammer that triggers radar detectors, but doesn't
seem to interfere with the police radars.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com
# http://www.LearnByDestroying.com AE6KS