I don't press PTT. In RX mode there is enough signal at the 24th harmonic.
Beware that some (older versions) go into an alternating 'on off mode', but that can be circumvened (for a while) by pressing the menu button.
...because of this I push the PTT
..and if you have not a BAOFENG the 24th harmonic (while pushing the PTT) works also with any other 70 cm TX
73 de Johannes