Jerry,
You can use an 1800 rpm sync motor or a 3600 rpm sync motor.
For 120 bps use 4 spinning electrodes on the rotor for the 1800 rpm,
or use 2 spinning electrodes on the 3600 rpm motor for 120 bps.
Old Teletype machines sometimes used suitable sync motors.
The type you want is the salient pole type. these types usually
simply say 1800rpm or 3600 rpm written on them. The
undesireable hysteresis sync motors usually have "hysteresis"
written on them.
You can also modify a normal 1750 or 3450 rpm induction motor
to make it synchronous by grinding or filing flats onto the armature.
The 1750 motor gets 4 flats, the 3450 motor needs 2 flats.
I show an electronic phase shifter circuit at my website which permits
the phase to be changed remotely while the coil is operating.
Cheers,
John