Understanding Scanning, Searching & Banks

Summary: The difference between scanning and searching, what CTCSS/DCS does, and the three types of bank the scanner uses to organise frequencies.

Scanning vs. Searching

Scanning steps through frequencies you’ve already programmed into channels, stopping briefly on each to check for activity. Searching is for frequencies you haven’t programmed – you give the scanner a range (or a preset service band) and it sweeps continuously through it, stopping whenever it finds something active. Anything interesting you find while searching can be saved into a channel on the spot.

CTCSS and DCS

CTCSS (Continuous Tone Coded Squelch System) and DCS (Digital Coded Squelch) are sub-audible signalling systems – sometimes called PL or DPL – carried alongside an FM transmission below the range of human hearing. Program a channel with the correct tone or code and its squelch only opens for transmissions carrying that same tone, which is useful in two situations: restricting a channel to a specific repeater or system, and separating out one of several stations sharing a busy frequency that would otherwise talk over each other.

Simplex and Repeater Systems

Most conventional two-way systems – aircraft, amateur radio, PMR, and plenty of business radio – use either a single shared frequency (simplex, generally line-of-sight, a few miles at most) or a pair of frequencies routed through a repeater sited somewhere high up for much greater range. Either way, all you need to program a conventional system into the scanner is the frequency (or frequencies) it uses.

The Three Bank Types

• Channel Storage Banks – 10 banks of 50 channels each, for frequencies you’ve programmed yourself. Group them however you like: by department, location, or interest.
• Service Search Banks – 7 banks preloaded with frequencies for Emergency, Freenet, PMR, Marine, Aircraft, CB, and HAM services, ready to search without any setup.
• Custom Search Banks – 10 ranges you define yourself, searched from their lowest frequency up to their highest.

Any of these can be switched on or off individually using the number keys, so you can scan or search just the subset that’s relevant right now.