This is a 1924 Crosley Model 51-SD AM receiver. This radio is similar to the Crosley 51 I have; the differences include only three
conrols and the sloped-front style of the cabinet on the Model 51-SD and four controls and a rectangular cabinet on the Model 51.
The radio is battery powered and has only 2 tubes and is a regenerative receiver. The first tube is the regenerative detector and the second
is the audio amplifier. Tuning is accomplished by turning the knob below the pointer dial until the desired station is heard.
Feedback for regenration is accomplished by pulling the center knob in and out and rotating the knob. Pulling it out increases the coupling and therefore the feedback.
Optimum operating point for regeneration is just at the point of oscillation. The knob n the right adjusts gain.
This is a small radio measuring only xx inches long, xxx inch high, and xx inches deep and is light in weight.
Below are pictures of the receiver with the lid open and the inside of receiver lid. Note that the warranty card is still present but unattached.
Below is a picture showing the inside of the radio.
Below is a picture of the rear of the radio showing holes through which to route wires connecting to the batteries.
Tube Compliment
Detector
AF Amplifier
Rider's Manual Page #
'01A or X'99 or 12
'01A or '12A '71A or X'99 20 or 12
The 01A vacuum tube operates with 5 volts on the filament. When using '01A tubes, +90 Volts is used for the audio
B+ and +45 Volts is used for the detector B+.
You can read about my Crosley Model 51 radio by clicking HERE
