How to check the Signal Strength of your blackberry smart phone

Those signal strength bars never tell the whole story; 
ever curious about what your wireless signal strength really is? 
On you BlackBerry keyboard, hold the alt key and type N M L L This will change your bars into numbers. 
You'll notice it's always a negative number; through a quirk in science 
and math a signal of -100 is better than a signal of -50, 
though anything in between should give you decent coverage. 
To change back to the signal bars, do the same thing again. Hold alt and type N M L L