I've read that during the early days of airliners radionavigation was accomplished through a two-tone radio signal that became continuous when the plane was oncourse. It would be REALLY cool to replicate that (using the VORs that are in the sim already, naturally). Could it be done??? Anyone know when this was phased out?David

According to my info, the system you refer to, was called LF. That evolved into NDB's, with the first VOR commisioned in 1947 & the VOR airways in place by 1952. I don't see dates, to know if the LF system was phased out before VOR's took over.L.Adamson