After reading about using a rotary dial phone with Obi202, I bought a Dialgizmo and dialing works fine with it.
However, the phone doesn't ring. In order to eliminate Dialgizmo from the equation I connected the rotary dial phone (Bell phone from 1979) directly to Obi202. It still doesn't ring. I increased the ringing voltage to 80V (20Hz, sinusoidal) and the phone doesn't ring. A regular/current phone rings fine.
Is there any other setting I should adjust in order to get the phone to ring?
Have you checked that the phone does ring on a standard phone line? Try it at a friend's or neighbour's house.
Indeed the phone didn't ring at friend's house (thanks drgeoff!) so I tried 2 suggestions I found on the web:
1. bias tension spring - see http://www.classicrotaryphones.com/forum/index.php?PHPSESSID=cfb2993e284048b4e38f309f56a1cb95&topic=2905.0 (http://www.classicrotaryphones.com/forum/index.php?PHPSESSID=cfb2993e284048b4e38f309f56a1cb95&topic=2905.0). It didn't solve the problem
2. wiring change – see below. The phone rings exactly like it did 40 years ago!
Does your Western Electric 500 telephone not ring but you can still dial a call and both sides of a conversation are audible? Then try moving the ringer's black wire to the network terminal marked "L1". See https://beatriceco.com/bti/porticus/bell/pdf/500_modification.pdf (https://beatriceco.com/bti/porticus/bell/pdf/500_modification.pdf) and https://beatriceco.com/bti/porticus/bell/images/500ringerrewiring.jpg (https://beatriceco.com/bti/porticus/bell/images/500ringerrewiring.jpg) for more info.
I never worked on phones but there is something in the back of my mind about some old extension plans here in the UK having the mechanical bells wired in series. Clearly a phone needs an internal wiring change to support that.
Maybe the US did something similar and your phone was jumpered that way.