If you've ever tried to distribute VoIP throughout your home and you have a lot of old phones, chances are you've run into problems with either the phones not ringing or ring improperly. This is because the typical landline supports a Ringer Equivalency Number (REN) of 5. The typical analog telephone adapter a REN of 3 or less. 1 REN corresponds to a single Western Electric telephone. Today's telephones are typically .2 REN or less.

The solution to this problem is the Ring Voltage Booster II, which boosts the available REN to 7.5. It also will boost ring voltage as low as 30VAC RMS up to 90VAC RMS. That should support 7 of those old phones and a couple of new ones, too!

Via Michigan Telephone