Since the first production of this model was released, several circuit changes have been made to improve the fidelity and volume of phonograph reproduction. These changes were made at two different times and are shown in Figures B and C.
Figure A show the original circuit. It is possible to check the phonograph input circuit on this radio without removing the chassis from the cabinet by the use of an ohmmeter, according to instructions shown.
TURN WAVE SWITCH TO PHONO POSITION, REMOVE PICKUP PLUG AND CONNECT OHMMETER TO PICKUP SOCKET MEASURE RESISTANCE WITH VOLUME CONTROL OFF AND FULL ON.

IF IT IS FOUND THAT CIRCUIT "A" OR "B" IS USED, CHANGE TO CIRCUIT "C".

10 K.C. FILTER ADJUSTMENT
MODELS CR - 136, CR - 146, CR - 147, CR - 148, CR - 149. CR - 152, CR - 153. irith the tone control set for maximum treble response and the Band Expander set in the High Fidelity position (accomplished by rotating the treble control to the right as far as possible), tune the receiver to a point between two stations of about the same signal strength on adjacent channels. If a 10,000 cycle heterodyne is heard as the boat note between the two carriers, it may be eliminated by retuning the 10 KC output filter by means of the 10 KC trimmer condenser at the rear center of the chassis. In the absence of such a signal source in the daytime, an ACCURATE audio oscillator may be used to feed a 10 KC into the volume control,
MODELS CR - 134, CR - 140, CR - 142, CR - 144, CR - 143, CR - 145, CR - 150, CR - 151. With the tone control set for maximum treble response, tune the receiver to a point between two stations of about the same signal strength on adjacent channels. If a 10,000 oyole heterodyne is heard as the beat note between the two carriers, it may be eliminated by retuning the 10 KC output filter by means of the 10 KC trimmer condenser at the rear center of the chassis.