DRA-100-RJ45 Speaker Jack - Detailed Operation:

The rear panel mounted 1/8" SPKR jack connects to the circuit board using a MOLEX
XH series plug and jack with red/black wires. The black is negative and is connected
to the circuit boards massive common ground connection.  Red is hot (positive).

The SPKR jack on the rear panel is a quality STEREO audio jack. The terminal for the 
ring is left unconnected. As such - it's compatible with mono or stereo speaker cables. 
If you have a radio that has a stereo speaker jack, as long as you use a stereo cable
(not provided) everything should work as expected without concern for damaging the radio.

There is no provision to switch receive audio between the SPKR jack and the RJ45 without 
physical / mechanical disconnection.  As such - I will caution you that you'll need to 
unplug the speaker wire from the back of the DRA when using receive audio provided 
through the RJ45 jack.  Additionally,  the 1/8" jack does NOT mute audio from the RJ45 
jack, nor does it take priority when the speaker cable is plugged into the rear panel 
of the DRA-100.  

Using the SPKR jack audio input doesn't require any jumpers to be installed into the 16 pin
 configuration socket.  Audio at the RJ45 jack is connected in parallel with the SPKR jack 
IF the receive audio has been connected / routed at / to pin 16 (SPKR) on the 16 pin 
configuration socket.  In other words, if there are two sources of receive audio, one at 
the RJ45 and one at the SPKR jack, they will be connected together and will interfere with 
each other if not properly isolated.

In summary - unplugging the 1/8" plug from the jack on the back panel of the DRA isolates 
and prioritizes receive audio coming in the RJ45 jack.  Unplugging the wire leading to 
pin 16 of the configuration socket isolates and prioritizes receive audio at the rear SPKR 
jack.  Each requires physical disconnection to alleviate a potential issue.

If you have concern - contact us.