Sixty years ago this month, the December 1956 issue of Popular Electronics carried this ad for what was probably one of the most expensive commercial crystal set ever marketed, the J.W. Miller Company Model 585 High Fidelity Crystal Diode AM Tuner Kit, which was also available assembled as Model 595.

The set was said to have received “overwhelming acceptance by the most critical audiophiles,” since it contained nothing to cause distortion. With a strong AM signal, it probably did provide the best possible fidelity. Its high Q coils gave it very high selectivity. Indeed, it was equipped with a vernier tuning dial.

A complete set of the assembly instructions are available at this link.  A nicely preserved specimen can be found near the bottom of this page.