am or fm mode for cb freq

AM is standard for CB communications, you wont hear much on FM except for some ham freqs (not sure what bands) and commecial broadcasting.

 

What are you trying to monitor? The vast majority of scanner traffic will be in FM mode. Civilian and military aircraft use AM (military can be found using FM at times). CB mostly uses AM and amateur radio uses many different modes with FM being the most widely used mode above 30 MHz.

 

That's an OK scanner for lots of stuff, including CB. It has an search bank pre-programmed, called "SR1", and unless you change anything, it'll default to AM when you're scanning that bank. Just remember that the stock antenna is pretty inefficient, just like any CB handheld would be, so you probably won't hear much unless you've got a "real" CB antenna hooked to it, unless the station you're listening to is remarkably powerful or remarkably nearby.
Cool scanner; lotsa folks use them for hearing analog trunked public safety systems.
If you didn't get the owner's manual with yours, it's available online for free download.
Hope that helps,
-- Handlebar --

 

25-27.405 MHZ is AM
HAMS ARE ON 29.600 - 29.700 and 52.525 MHZ FM
27.41- 118 Mhz FM
118 - 138 mhz AM
2 Meter FM repeaters are on 145 - 147 mhz
138- 512 Mhz FM

700 mhz and up is trunking FM

CHECK LOCAL LAWS ..... If you run it in your car or truck HERE in Florida it is legal.