In the spirit of being prepared to be of aid to someone in a disaster, I purchased an old Heathkit Phone Patch. Phone Patches used to be as common as dirt, but now seem to be rarely used. I think having one in any station would be an asset.
My questions revolves around the proper telephone interface device which the instruction manual states as a requirement for use between the phone line and the phone patch proper. What exactly is this interface? I suspect it is most likely a simple isolation transformer, designed to keep the amateur from superimposing DC voltages onto the phone line in order to protect the repairman and equipment. I would have thought the phone patch would contain an isolation transformer to keep the phone companies ringer voltages out of the ham equipment.
But the manual was quite clear about the requirement for such a device.
I did a Google search and came up dry. Can anyone who has used a phone patch in the past, describe this device and possible where to obtain one?