At our local museum we have rigged up the depot telegraph keys and sounder with a battery so demonstrations of telegraphy can be done for visitors. An interesting question has come up which I’d like to share here for any help that can be provided from the very knowledgeable railroaders on this board.

Since the old railroad telegraphs operated with battery voltage, which would be DC instead of AC, and since DC cannot be transmitted over long distances nearly as well as AC, how were the signals transmitted reliably over the great distances required for railroad operations? I’d think this would be especially critical with what I understand were pretty low voltage levels of the battery sources.

Many thanks for any help you can offer!

Robert