Antenna Question

[_DeS_]

Hey Guys...just quick question. I was watching COPS the other night and it seems that a lot of the police cars have several of the same antenna on them in a cluster just past the light package, any idea why ? wouldnt 1 be enough ?

Thanks for any info.

Regards

 

[n211cr]

If there are 4 in a square normally its for lo jack, the 4 identical antennas allow them to tell a general direction the signal is coming from.

 

[N_Jay]

If there are 4 in a square normally its for lo jack, the 4 identical antennas allow them to tell a general direction the signal is coming from.

If it is 4 in a square it is usually LoJack. (as said) The four antennas feed a receiver that is able to decode phase differences in the recovered signal and can very accurately determine direction.

If it is 3 in a triangle it is for "Bank Bag" type systems and works in a similar way but is less accurate to the rear of the vehicle.