Palm VIIX Handbook page 136

To monitor signal strength in the Diagnostics application:
Tap the Diagnostics icon
Both the bar graph and the number represent the signal strength:
The graph represents signal strength as a series of bars. The more
bars displayed, the stronger the signal.
The number represents signal strength as a percentage. The higher
the number, the stronger the signal.
You can also monitor signal strength from within web clipping
applications and the iMessenger application. A small version of the
same bar graph you see in the Diagnostics application appears
onscreen when you're performing a wireless transaction.
In web clipping applications
Page 128 Web Clipping Applications and the iMessenger® Application
.
More bars =
Stronger
signal
In the iMessenger application