I picked up a Bearcat 4 that won't scan.I don't have a manual so I was hoping someone might know of a common problem.The audio Ic seem to be good but when you turn the squelch down there doesn't seem to be enough audio.
Connecting a signal directly to the audio IC produces enough audio.

Hi,
Normal operation for that type of scanner is that you adjust the squelch until the audio noise floor drops to zero, and then the logic circuitry switches to the next channel, and so on, until an RF signal is strong enough to overcome the squelch setting, and the scan stops on that channel until RF level drops below the squelc setting.

The scanner may be functioning just fine, it may just be that there are either no crystals in the unit, or those frequencies are not in use in your area. You can emulate the crystal with an RF generator set at low output level, and fed through a cap on each output terminal, and plug them into the correct crystal slot.

You can get a copy online of the old manual here:
http://209.145.176.7/~090/awh/bearcatting.html

:I picked up a Bearcat 4 that won't scan.I don't have a manual so I was hoping someone might know of a common problem.The audio Ic seem to be good but when you turn the squelch down there doesn't seem to be enough audio.
:Connecting a signal directly to the audio IC produces enough audio.
: