I moved into a new home and have a doorbell transformer that is reading 16V at the transformer itself and on the wires coming right out of the transformer. The wires, though, are only showing ~7.5V at the site of the doorbell after they travel from the transformer to the doorbell. Both the transformer and wires are likely pretty old (wires have the old string/cloth covering).
I've checked for a solid connection, which we have. Any idea what the likely culprit is? Is it possible that the natural resistance of the wire is causing the drop? (I don't think so but just wondering...). I can access the wire in our attic for most of its run and it appears to be fine and intact, so I'm having a hard time figuring out why the voltage would drop so much. Would love any advice on what it might be or how to troubleshoot before I go to the trouble of trying to replace the wire entirely.