atcomsystems.ca/forum Forums Other TDM Phone Systems Other Telephones & Systems Cortelco 2500 schematic

I'm looking for a Cortelco 2500 pictorial drawing. I connected an dual gong with four wires to the network and it changed the phone so it doesn't hang up.

I understand the older networks had an internal capacitor but since this phone was designed for a two wire ball bearing gong ringer maybe the capacitor has been removed?

Interesting, the issue likely has to do with resistance being too low when the phone is on-hook.

Something like this?

Cortelco 50-500-105

The capacitor is between terminals A and K on the network.
Are you sure that the ringer consists of 2 separate coils, and you have the correct leads for each coil? It sounds like you've put a single coil across Tip and Ring.
Sometimes ringers have 4 wires, but it is still a single coil ringer, 2 of the wires are taps for different impedances, they are taped and stored. One lead goes on Tip, the other on A, and a jumper is placed from K to Ring (or an off-normal hookswitch pair makes the bridge when the handset is in the cradle.