Here Are some Police Scanner Facts
A Police scanner is great to have during times of bad weather. If you have ever had a standard (analog) Scanner, over the past 10 years you probably have noticed that you don't hear as much on it as you used to. Thats because in the past decade the trend has been that most states have moved their communications to a digitial tower based network system, Known as APCO-25<-see definition at Wikipedia)
. These tower network systems have at least one tower per county in each state they are in. The radio signals coming off of these towers are digital and cannot be received by an older standard analog scanner. To receive Digital Police Radio Signals you must have a digital scanner. When shopping for a new scanner a digital scanner will state in its specification list that it can receive digital radio signals. If it does not state that it can receive digital signals, then it WILL NOT and do not assume that it will. You will have to pay a higher price for a digital capable scanner then you would for a cheaper one and I do not know of any cheap digital scanners, although the price of digital scanners have been trending somewhat lower since spring of 2010
Emergency Power for Police Scanners
Now that you have a scanner you should consider a backup power source for it. Your scanner will be of no use to you if the power is out and you can't use it and thats when you need it most. A great idea for backup power for your scanner is a Backup UPS<-see definition at Wikipedia) like what you would plug a PC into. Backup UPS's go for as low $130.00 and would probably run your scanner for at least a few hours. But you may also need a power source for your scanner that will lasts longer then that. That is where the idea comes in of a power inverter that runs off of a car or favorably know as "the poor man's generator". A small lighter socket inverter for a car, at 90 to 120 watt output, is big enough to run your scanner. You could also consider a 400 to 700 watt car battery clip on model and use it to power other things as well. In using either one, you will have to keep your car running and run a drop cord from the car into the house. If you have to use your car and a power inverter as a source of power, your car must be outside in a well ventlated area and NEVER attempt to do this with your car in the garage.
This Author has owned nearly a half dozen police scanners at the same time for more then 20 years and during an ice storm here in Indiana in December of 2008, He powered his police scanner, his laptop and other house hold items off of a car battery inverter.