Transmitter detector for use in a moving vehicle

Apparatus for detecting the presence of a radio transmitter of known frequency and power within a predetermined distance of a moving vehicle, said apparatus comprising:

• radio receiver means for receiving a signal from said radio transmitter and providing a received signal;
• signal detector means responsive to said received signal for providing a channel active signal during the time that said received signal exceeds a prescribed level;
• timing means responsive to said channel active signal for generating a timing delay signal having a duration based on an estimated speed of said vehicle relative to the power of said transmitter;
• and
• alert means responsive to said channel active signal and said timing delay signal for generating an operator alert during said channel active signal and during said timing delay signal.

Detection apparatus for modification of a radio receiver to detect the presence of a radio transmitter of known frequency and power within a predetermined distance of a moving vehicle, said apparatus comprising:

• sensing means responsive to a received signal from said radio receiver for providing a channel active signal when said received signal exceeds a prescribed level;
• timing means responsive to said channel active signal for generating a timing signal having a duration based on an estimated speed of said vehicle relative to the power level of said transmitter;
• and
• alert means for generating an operator alert during said channel active signal and said timing signal.