🚀 go-pugleaf

In article <1123@pasteur.Berkeley.Edu>, max@trinity.uucp (Max Hauser) writes:
> In article <20271@bu-cs.BU.EDU>, madd@bu-cs.BU.EDU (Jim Frost) writes:
> 
> > In article <4596@pucc.Princeton.EDU> MJSCHMEL@pucc.Princeton.EDU writes:
> > >Do you think it's feasible (forget about legal for the moment because I'm
> > >speaking, of course, hypothetically) to build a radar TRANSPONDER? ...
> > >[It] would send back a signal to your friendly Highway
> > >Patrolman on his X or K or whatever that would register a perfectly
> > >legal double nickels on the Law's satanic little radar gun's readout.
> > >[...] LET ME KNOW WHY THIS COULD(N'T) WORK.
> > 

Radio-Electronics (August 1986 issue) gives construction details for a
'radar-calibrator' which does exactly what you want.

Police radar works on the principle that the doppler shifted return
signal beats with the internal reference signal, the beat frequency is
proportional to the speed of the car.  Simply AM modulate an X or
K band rf signal with the appropriate frequency (in the audio or sub-
audio range, depends on desired speed and radar freq) and it will
over power the beat mechanism in the radar, causing it to lock on
to your 'programmed' speed.

John Logajan umn-cs!hyper!ns!logajan
Network Systems Corp
7600 Boone Ave
Brooklyn Park, MN  55428