wanted System Key File

[underlift]

Hi All Im trying to fix my EF Johnson 5300 with missing info, But I need a System Key or a Generator for SSID 782d Can anyone direct me in the right way, It's missing the Mowat Tower #40. The person that set it up originally has moved out of the Country.

Thanks For Any Help
P.S. this system is Monitor ONLY No Tx.