Bakelite phone - making it ring! - Page 3 - UK Vintage Radio Repair and Restoration Discussion Forum

Station X · 8th Sep 2025, 1:08 pm

For a public exchange ringing current was 16 2/3 (17Hz) from a vibrator or latterly 25Hz (half mains frequency) from a ringing machine.

Cadence 0.4s on, 0.2s off, 0.4s on, 2s off. ie ring, ring, pause, ring, ring, pause......

The cadence allowed more bells to be run from the exchange as there were, I think, two phases of ringing current. While half the bells were ringing the other half were silent.

8th Sep 2025, 1:08 pm	#41
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 22,803	Re: Bakelite phone - making it ring! For a public exchange ringing current was 16 2/3 (17Hz) from a vibrator or latterly 25Hz (half mains frequency) from a ringing machine. Cadence 0.4s on, 0.2s off, 0.4s on, 2s off. ie ring, ring, pause, ring, ring, pause...... The cadence allowed more bells to be run from the exchange as there were, I think, two phases of ringing current. While half the bells were ringing the other half were silent. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.