This simple circuit allows two transceivers to share a common amplifier and antenna. It was designed for LF contests in a multi-operator single band entry.
The transceivers share a separate receive antenna installation (which is disconnected when either transceiver goes to transmit). A suitable circuit – which is placed in the common PTT-line output from the “FOW” controller – can be found here.
Note that the controllers on each transceiver must be set to have at least 30ms delay between PTT line assertion and the beginning of any RF generation.