a. Direct wire or public telephone system interconnection. Prepare sending and receiving LDFs
for operation using field wire or public telephone system interface and internal FM modem.
NOTE: If public telephone system lines are to be used, an adjustment to the FM modem CCA
attenuator is necessary to change the 0 dBm value to -9 dBm. The attenuator is set to 0 dBm
when delivered from the factory. Unit maintenance should be notified to perform this
b. Install jumper plug assembly on signal connector J1 (Figure 7).
c. Connect LINE binding posts on sending LDF to LINE binding posts on receiving LDF using
either field wire or public telephone system lines (Figure 8).
d. Connect telephone set to PHONE binding posts.
Figure 8. Typical direct wire interface cabling diagram.