Jensen PA500 - Manual (Page 2)

The JENSEN PA500 is a universal public address system
that can be utilized as a stand alone PA (when connected
to speakers) or operate in conjunction with any existing
radio/speaker set up.
The PA500 system amplifier connects in line between the
vehicle's radio and the installed speakers.
The installed radio will operate normally. When
the microphone is activated by the "Push to Talk" (PTT)
switch on the microphone, the speakers are electrically
disconnected from the radio and engaged with the PA.
The microphone triggers activation of the PA through
the same speakers (muting/overriding the radio source).
There is no need to adjust PA volume at the radio since
the PA volume can be set using the volume/gain control
on the PA500 itself. If the PA500 is installed in an enclosure
the volume level can be pre-set by the installer.