TELEPHONE TO TRANSCEIVER INTERFACE
(Using A Hybrid Transformer)
By: W5FJS

For about $20 to $30 you can build a box that will enable you to use any telephone to operate
your transceiver without having to modify the telephone.

The circuit is very simple. The Hybrid circuit is two Magnetek transformers, part # TY-302P,
available from Mouser for $8.33. Part # 553-TY-302P. The other parts you may have in your
goodie box. This circuit requires 600 ohm termination, however, in this application the chosen
values are very forgiving. Read more about hybrid circuits.

Thanks to Norman, K5EBL, for his part in putting together this project.

If you would rather buy one, JK Audio has the TAP-1 for $245. It appears to basically be the
same as our home brew box.