Comment Re:Cops and Cell Phones (Score 1) 142
Actually any good digital scanner now can pick up trunked radio conversations very well. There are a couple systems that they can't pick up, but the Uniden BC296D or 796D can do most. RadioShack has their own model too, the PRO96 if I recall.
The reason the antennas are so small is because the typical frequency of a trunked radio system is around 800mhz give or take. The antennas for this are comparable to mobile phone antennas. Back when the public safety systems were on CB frequencies you needed giant whips. When they were in the 156.000 Mhz range you could get away with a smaller whip, but now that they're getting near Ghz ranges the antennas have shrunk considerably. The other reason they're down to the size of Sirius antennas, is because you can shrink an 800mhz antenna down considerably when all you need it to communicate on is a very small range of frequencies.
Lastly, A field agent could talk to another agent 70 miles away pretty easily if there are enough towers in enough critical locations. Michigan has implemented this for their state police. A trooper in the UP can talk to a trooper near Detroit through this network of towers. Everything on their network can be picked up on a scanner for around 600 US dollars, with the exception of the encrypted communications.
The reason the antennas are so small is because the typical frequency of a trunked radio system is around 800mhz give or take. The antennas for this are comparable to mobile phone antennas. Back when the public safety systems were on CB frequencies you needed giant whips. When they were in the 156.000 Mhz range you could get away with a smaller whip, but now that they're getting near Ghz ranges the antennas have shrunk considerably. The other reason they're down to the size of Sirius antennas, is because you can shrink an 800mhz antenna down considerably when all you need it to communicate on is a very small range of frequencies.
Lastly, A field agent could talk to another agent 70 miles away pretty easily if there are enough towers in enough critical locations. Michigan has implemented this for their state police. A trooper in the UP can talk to a trooper near Detroit through this network of towers. Everything on their network can be picked up on a scanner for around 600 US dollars, with the exception of the encrypted communications.
