Hi Eric, to set your PL tone, press the D key, which is function and then
the 2 key.  I think they default at 88.1 or what ever that is, so you
just need to turn the knob to the right until you get to the PL tone you
want.  For example, if you want 100Hz, you would turn the knob 4 or five
times.  You can try to key up the repeater in question while you are in
the PL set mode, until you find the right tone, then, press the 2 key
again to save the setting.  To turn on the PL, press D followed byy 1,
and you will be toggling through the choises.  If the PL is off, the
first press will turn it on, the second press will turn on decode as well
as encode, and the third press turns both encode and decode off.  YOu can
tell when you are in the encode decode mode, as you won't hear any white
noise, even with the squelch wide open, that is, all the way to the left.
 If you have any more questions, feel free to give me a call at:
480-671-7912

I also have the manual for the 470 in text format, if you need it.

73 and HTH:
John