although these color tubes don’t seem to be for the model of TV being followed during the rest of the films. At about 7:07 they call them “Color Kinescopes”, an early name for RCA’s CRT ...

The 4K RCA NEXTGEN TV sets will be available in 55-inch and 65-inch sizes. The 65-inch model features a Mini-LED QLED screen with 664 zones and offers up to 1500 nits of peak brightness.

designed it to wire an RCA Victor "phonograph" turntable to the radio to amplify the sound. Only one cable was used as it carried a monophonic signal, not stereo. See A/V ports and phone connector.