telephone outlet transformer

[S. Centel]

Is it common to have a pigtail plug-in (outlet) transformer connected to the telephone wires? I have a PCI Transformer Model 0501 0569. On the inside it reads LINE 685-9646 LOAD. I unplugged it and nothing happened. The phone and all electrical still works. Is it necessary?

Thank you,
S. Centel

[Jim Port]

It might be from when phones had lighted keypads. Is it connected to the yellow and black phone line?

[neal lewis]

The transformer was required for the lighted dial Trimline phone introduced in the 60's.

[S. Centel]

We built the house in 1991...I will try to take a picture in the near future to show the connection. Thanks for your response.

[Billy Stephens]

We built the house in 1991...I will try to take a picture in the near future to show the connection. Thanks for your response.

Sounds like a power line transceiver.
phone line capable alarm,
( early but possible more prevalent mid 90s.) ethenet power