Though one of the earlier posts in this thread seemed to imply that microfilters have their own ring capacitor built in? If this is true you wouldn't need the third wire.
Can anyone confirm if they do? Andrew Iain Street wrote: >> The Bell Ringer history on KITZ has a fascinating story about wire >> No 3 and its roll in the old scheme. >> Clive >> >> > > It's still needed to get phones on secondary sockets to ring. >
