I have a question about logging recorders that are used at police
headquarters for example to record communications. I understand that
they record the audio received by the receiver from the mobile unit
and they also record the transmissions made by the dispatcher on the
local mic. How exactly is the logger connected to the radio system.
Where are these two audio sources combined? There is no single
connection in a typical radio transiver to get both the transmit audio
and the receive audio.

The reason I want this detail is to understand what happens when the
dispatcher "talks over" one of the mobile units or a mobile units
"talks over" the dispatcher. Is there any way that both audio signals
can get recorded together? I understand in a typical 2 way radio
transceiver, when it is transmitting, it cannot receive. But in a
more complex system typically used for police communications that may
involve multiple remote satellite voting receivers, are there any
conditions where both the active Rx and the dispatchers mic audio
might both get recorded on the logger together?

Does anyone know the details of how a logging recorder is typically
connected to a complex communications system? Is the dispatcher mic
sometimes always recorded even when the transmit button is not
pressed?

thanks
Mark
WB2WHC