The Crosley 50 is a
single tube regenerative that was built in 1924 by Powell Crosley in
Cincinnatti. The '50 is the smallest of a series of radios that
Crosley produced in 1924. The 50 uses a spiderweb coil for tuning
and a sliding spiderweb for the tickler regeneration. The receiver
is tuned with a book capacitor which is wired in series with the
antenna. A long antenna should be used on this receiver in order to
reach the low end of the band. This radio uses the capacitance of
the antenna to help tune this radio. It is designed for high
impedance headphone use.
The 50 is essentially the same as the detector stage of the model 51. The schematic of the 51 is available here. The headphone terminals go where the primary of the interstage transformer is connected in the 51. The second tube is eliminated.