Driving automobiles





Radio interference with radar units

A friend of mine was doing 45 in a 45 zone the other day, while
talking on his ham radio.

Next thing he knows, he has been pulled over for 59 in a 45.  He
firmly believes he wasn’t speeding (I’ve ridden with this guy, he
typically drives the speed limit) and I believe him.

He has heard of cases where radar evidence has been thrown out of
court due to interference from vehicles which were broadcasting at the
time they were clocked, on CB radios.  He feels that if radars can be
fooled by a 5 watt CB, they are likely to get pushed around by 50
watts of 2 meter.

Does anyone know any specifics?  If so, please mail me at the below
addresses.

Followups set to rec.autos.driving.


Nick Simicich – uunet!bywater!scifi!njs – n…@watson.ibm.com
SSI #AOWI 3958, HSA 318, NAUI #14065
Join the movement —  turn ‘to bush’ into a verb.

posted by admin in Uncategorized and have Comment (1)






One Response to “Radio interference with radar units”

  1. admin says:

    In article <1992Jul21.023640.3…@scifi.uucp> n…@scifi.uucp (Nicholas J. Simicich) writes:

       A friend of mine was doing 45 in a 45 zone the other day, while
       talking on his ham radio.

       Next thing he knows, he has been pulled over for 59 in a 45.  He
       firmly believes he wasn’t speeding (I’ve ridden with this guy, he
       typically drives the speed limit) and I believe him.

       He has heard of cases where radar evidence has been thrown out of
       court due to interference from vehicles which were broadcasting at the
       time they were clocked, on CB radios.  He feels that if radars can be
       fooled by a 5 watt CB, they are likely to get pushed around by 50
       watts of 2 meter.

       Does anyone know any specifics?  If so, please mail me at the below
       addresses.

    First ask these questions:

    Are you %100 sure you weren’t speeding?

    Was there other factors that may have led to an erroneous reading?
    Things like other traffic before or behind, etc.

    I know someone who did beat a speeding ticket on just this point.
    Apparently some of the radar units use an IF that falls right into the
    amateur 2 meter band.  He was able to show mathematically how the
    frequency he was using would show an apparent doppler shift.  He was
    also using a lot of power at the time.

    In his case his professional credentionals were enough to be
    convincing in court.  In your friend’s case is he going to be able
    to show his case convincingly?  Remember that you may be innocent
    until proven guilty but radar and the cop’s word are generally
    accepted as evidence so that puts the ball back in your court.

    good luck, jv

    "Fickt nicht mit der Raketemensch!"
     _____
    |     | Johnathan Vail     v…@tegra.com     (508) 663-7435
    |Tegra| j…@n1dxg.ampr.org    N1…@448.625-(WorldNet)
     —–  MEMBER: League for Programming Freedom (lea…@prep.ai.mit.edu)







Place your comment

You must be logged in to post a comment.