Funkwerk FT4 Operating Manual page 84

80 Operation
Group calls
‹PTT (transmit key)›
2. Push key
After a short time, your speaking enable signal is transmitted unless another
subscriber is transmitting. The display additionally shows your name or your call
number (ISSI).
‹PTT (transmit key)›
3. Keep
4. After speaking, release key
You may now be able to hear other subscribers.
As soon as no more subscriber answers, the connection is disconnected after a
pre-set time.

Done.
and keep it pressed.
key pressed while speaking.
‹PTT (transmit
key)›.