Kovalick's comments

On: The evolution of annunciator signaling for telephones

[Kovalick]

Generating 90 VAC at 20 Hz was a challenge in the early days of exchanges. Check out Calling315.com for more on ringing generators

https://www.calling315.com/ringing-machines

On: The evolution of annunciator signaling for telephones

[Kovalick]

Great point! I will add that to the pages on Annunciators. Thanks for the idea!

On: The evolution of annunciator signaling for telephones

[Kovalick]

I agree with you that electro-mechanical is very cool. Check out Calling315.com for a complete coverage of vintage (relay based) telephone exchanges. The site has 70 articles on switching systems from 1877 until 1970. All for fun...

On: The evolution of annunciator signaling for telephones

[Kovalick]

Jimmy, thanks for the comment-- check out Calling315.com for more on the very early days of how the T and R got started. It was JJ Carty of AT&T (1900) that decided to use Tip and Ring and not a single wire and earth ground from each home.