I did not know that the landline carries AC superimposed on the DC V. The only reason I put a multimeter on it al all is that my landline works sporadically. Usually when it is not working the ringer shorts out so quickly it can't be answered. I measured ~ 47V DC and 103.4 V AC. Reading this forum tells me that 90V AC is delivered when the phone rings. I can measure 103V 24/7. Why does this happening and is it the cause of my service problem?