Uniden GPS Setup
From InterceptRadio.com Wiki
Some models of Uniden scanners (BCD396XT and BCD996XT) will accept a GPS connection on their serial port. Provided your scanner is programmed correctly, it will automatically scan frequencies in your immediate area while locking out frequencies for areas far away. This can be very handy if you are on the road often.
For this example we will use a Uniden BCD396XT handheld scanner. Please look at the following picture:
On the far left is a BCD396XT handheld scanner. Connected to it is the serial cable which is included with the scanner when it was purchased.
The white device in the middle is a 9 pin null modem adapter.
On the other side of the null modem adapter is a GPS adapter cable. The left side of the adapter cable is connected to the GPS and the right side is connected to the power source. See the white cable on the right side ? The GPS adapter cable originally had a round male plug on this end. We cut off the plug and connected the red and black wires to a USB printer cable (the white cable). We then connected the USB plug to a 12 volt USB adapter. This was done because the GPS requires 5 volts to operate.
This setup is extremely simple to put together. Here is your shopping list.
GPS: GlobalSAT BR355 ($41 at Amazon)
GPS Adapter cable: GlobalSAT BR305-RS232 ($12 at Amazon)
Null modem adapter: StarTech NM9MM ($5 at Amazon)
The null modem adapter is needed for the BCD396XT (handheld) scanner. You do not need the null modem adapter for the BCD996XT (mobile) scanner. Just plug the GPS adapter cable straight into the back of the scanner.
You can save $26 by skipping the adapter cable / null modem and buying your own 9-pin connector.
The USB printer cable and 12 volt USB adapter can be found for a couple dollars.