Chris,

The TMG-707 can search for PL tones.  Before you start the search,
you have to be sure that the radio is in PL or CTCSS mode, which is
accomplished by pressing the second small button from the left so
that a high beep is heard.  The first high beep is PL, the second is
CTCSS, and the low beep means neither one.  Once the decoding mode is
selected, press the Function button (first one on the left), followed
by the decoding mode button (second from the left).  The radio will
scan for a tone, and will beep when it finds the correct one.  Press
OK (the Power button) to store the result.

Steve