The plans for this “modern crystal set” appeared in the December 1946 issue of Radio Craft, having been sent in by one W.J.E. Spain of Toronto. The author reported that the set was both selective and sensitive. He had six local stations in his area, ranging from 1000 to 50,000 watts, including a police station, and could pull in all of them with no interference between stations. All had good volume on headphones, and four stations were strong enough to operate a horn type speaker, with a 75 foot antenna.
At night, WLW Cincinnati and WENR Chicago came in like strong locals. The Buffalo stations were also heard regularly at night.
The switch marked S/B was used for selectivity. In the S position, the set was very selective, and in the B position, tuning was broad. He tuned with the switch in the B position, and then switched to S to cut out interference. Tuning was accomplished with S1 and the variable condensers, one of which was used for fine tuning.
The crystal was a 1N23, a germanium crystal which had been used as mixers in radars. They appear to be available today, or other diodes such a 1N34 would probably provide good results. For ideas on sourcing parts, see our crystal set parts page.