http://www.miklor.com/COM/UV_Squelch.php has some suggestions.

If you set the levels higher than 60 or so you may only be able to hear extremely strong local signals.

Setting levels to 0 will not open the squelch on my two radios.

Squelch menu setting 0 ignores whatevel the level it is set to and opens the squelch at all times.

Tom

Now that the expanded UV-5R Service Settings for Squelch are accessible through CHIRP (thank you!), does anyone have recommendations for good settings there?
Thanks.
Michael, W1NBV