spd 3 antenna triangle config?

[jparks29]

Some Seattle PD cruisers have a triangle pattern of vhf antennas to the rear...

Reminds me of Lo-jack, but lo-jack uses four in a square, not 3 in a triangle..

Someone told me it was for a 'rat pack', that's replacing dye packs, if there's a bank robbery it's thrown in with the cash and acts much like lo-jack through triangulation..

Any ideas?

 

[commstar]

LoJack is four VHF whips in a square pattern,

Pro-Net is Three VHF whips in a triangular pattern like a arrowhead. Pro-Net: the tip of the arrowhead points to the front of the vehicle.

Pro-Net has been in use since the early 90's and seems to have lost some popularity despite being very effective in many places. I believe this is due to the banks in a certain Pro-Net service area having to pay a monthly fee to the company. I have used the system but not in Seattle and am a fan.

The fee is commonly divided equally amongst the number of banks in the given service area. As bank robberies drop, banks drop out of the program feeling they are getting no value for their fee (makes no sense to me). Those banks that remain end up paying more each month as there are less banks in the pool.

Best,
Mike