Federal built high quality receivers though some of their circuits and mechanical devices seem rather “Rube Goldberg” at times. The DX Type-58, from late 1922, was designed for the enthusiast and the metal cabinet seems to show this. Selling price was somewhat expensive for a four tube set – $123. Federal’s workmanship was excellent, however their documentation is vague at best. It is interesting that Federal was so afraid of a RCA-Westinghouse law suit over the Regenerative Detector patent, they didn’t tell owners (in their instruction manuals) that their radios could be set to regenerate and therefore significantly increase performance. Having “Regeneration” in print in an operator’s manual would have been as good as an admission of guilt by Federal. Most owners figured out the adjustments anyway and the radios were fairly popular. By setting the “COUP” control to near “0” and advancing the “AMP” control to near the oscillation point, the DX Type-58 (and most other Federals) can be quite sensitive and selective receivers. Unfortunately, as a child, I connected the radio, that was designed for battery level voltages, to 110VAC. It fried one of the coils (see pictures).