The Gleichstromwecker (DC Bell) is a ringer module that operates on 3 Volts DC. The operating voltage was typically supplied by two 1.5 Volt T30 batteries wired in series. The module and batteries were designed to be connected as optional accessories on the three W/WB terminals on a field switchboard and a Amtszusatz. It would alert the operator if there was incoming calls.
The Gleichstromwecker is rather rare and difficult to come by outside of the EU. So, I decided to make a reproduction out of readily available components. First, I obtained a cheap bell from the hardware store. The bell operates quite nicely on 3 Volts DC. I mounted the bell to a small sheet of wood. The terminals were made from brass strips with posts salvaged from a US military surplus field telephone wire spool. The cover is made from an electronics metallic project box. The box was cut and drilled to fit over the bell and terminals.
Check out my new book on WW2 German field telephone equipment… https://www.lulu.com/en/us/shop/rotwang-manteuffel/world-war-2-german-field-telephone-equipment-a-basic-guide-for-reenactors-and-historians/paperback/product-976w9q.html?page=1&pageSize=4
WW2 German Field Telephone Equipment 