This is an in-depth restoration video of an Echophone EC-1 Receiver. There is also a very descriptive explanation of how a superheterodyne receiver works. This superheterodyne description also includes a complete alignment, IF and RF. See how to perform this alignment using various test equipment.
Check out below, for "John's" website containing great info, and the original radio advertising for this neat little Echophone EC-1 receiver.
Johns site : http://www.geojohn.org/Radios/MyRadios/EC1/EC1.html
Thanks to Larry for this receiver!