Mercier 24/48 Line Set
(click on picture for high resolution image)
This set was made by Murry Mercier Jr. and Sr. in late 1928. It has two disks, each about 12 inches in diameter, which can be interchanged. One is for 24 line transmissions, the other for 48 lines. You can see this receiver in this photo.
This is a picture of the 24 line disk.
This is a view of from the top of the unit (viewing side of the set is toward the top of the picture). In the top compartment is the motor, connected to a knife switch of the right side, which changes the motor's rotation direction. Just below the wooden divider is the disk. Below the disk is a transformer which supplies the power to the motor.
This is a view from the rear, showing the 45 line disk, with the stepdown transformer for the motor.
This is another picture of the rear of the set, with the neon tube in place. The small board on top with a hole in it supported a small magnifying lens.