Most prewar Philco radios never had a back (thin fiberboard or other material, sometimes metal, used to cover the back of the radio cabinet) on them. The first Philco models to use a back were the early 1932 models 90X and 112X – and the backs on these covered the speaker compartment only, not the radio chassis.

As Philcos began to make AC/DC radios in 1933, these also had backs on them. Examples include models 53C, 54C and 28C. Model 45C also had a back.

Many of Philco’s higher end 1938 console models were made with backs. Most of these backs have been lost over the years, leaving only the telltale clips which once held the backs in place.

Most 1940 Philco table models had backs, since the loop antenna was fastened to the back.

Still, the vast majority of Philco radios made before World War II never had a back on them.