Okay, one more time.
The 0747, by itself, is only a power supply. It looks like this:
http://www.channelmasterstore.com/CM..._p/cm-0747.htm
The amp will look like this one although, if it's the older one, it will have two inputs:
http://www.channelmasterstore.com/TV..._p/cm-7778.htm
By itself, the power supply would do nothing. Go outside and look and see if there's a box mounted near the antenna, perhaps on the mast, perhaps somewhere else along the coaxial cable run. If your installer stuck a power supply in your system without an amp, he didnt know what he was doing.
If you remove the power supply from a CM amp, it turns into a 30 dB attenuator which will wipe out anything except your strong local stations.