29. Battery installation. With the telephone sitting on a desk or level area with the binding posts to the
right the battery compartment is in the right rear position of the telephone as you look down on it.
a. To insert batteries, the compartment must be opened and checked for foreign matter. To
open the compartment, turn the thumbscrew counterclockwise and lift the cover. (See Figure 1-14.)
Figure 1-14. Battery compartment cover.
b. Polarity of batteries is important. Check the cells before inserting to forego any problems.
The top of the cell with the button on it is the positive (+) and the bottom of the cell that is flat is the
negative (-). (See Figure 1-15.) Insert the batteries in the compartment as shown in Figure 1-16.
c. Visually double check the polarity of the four cells. Carefully close the battery compartment
cover and lock it. Do this by turning the thumbscrew clockwise.