To connect the antenna, just screw it onto the SMA connector at the top of the scanner.

If you want to use an external antenna, attach the included SMA/BNC adapter to the scanner's SMA connector.

Then, connect your external antenna to the BNC connector.

Note: Always use 50- or 75-ohm, RG-58, or RG-8, coaxial cable and the supplied SMA/BNC adapter to connect an outdoor antenna. If the antenna is over 50 feet from the scanner, use RG-8 low-loss dielectric coaxial cable. Cable loss increases with higher frequency.