Eng
Connect the DC supply (battery)
The Universal pre-amplifier has a 24 Vdc input (terminal screw), which you can use to connect a back up power supply,
e.g. batteries. You can earth the unit to increase the electrical stability of the system. The unit is protected against
reversal of the battery polarity.
Caution
The connection cable must have an in-line fuse. Use the type of fuse as mentioned in the illustration.