If you can't find them at Radio Shack, try www.sandman.com
in Chicago. All kinds of phone stuff.
> Use of the Radio Shack box is easiest on POTS lines...if you
> are trying it on a KSU, make sure you do this on ANALOG
> lines only...the digital circuits do NOT comply with the
> above obviously and will be proprietary with any system.
> Teltone made some relays that were great for signaling on
> ringing AND offhook...
> but they are out of production.