Motorola iDEN i870 User Manual page 187

For Private calls, group calls, and SDG calls, use
the remote PTT button as you would the PTT
button on your phone.
Note: When using a headset, the PTT button on
your phone works the same way as when
you are not using a headset. Sounds
associated with Private calls, group calls,
and SDG calls are heard through the
headset.
Using a Remote PTT Button
175