The 1940's were interesting in that the American involvement in the war put all manufacturing on hold from 1942 until 1945.  Production resumed in 1946, with largely the same designs as before the war.

Starting the 1940's, some trends were large consoles that looked like juke boxes, with presets and tuning eyes being a fixture of these sets.  Large horizontal table radios were also popular in the early 40's, Philco's slant-fronted models being some of the most memorable.  Small portables became available, like RCA's BP-10.  These were much smaller than the large suitcase-like models that came before them.

New tubes developed in the 30's allowed for cheaper designs that omitted the expensive power transformer.  These transformerless radios actually started in the 30's, but became the default design for most table radios just before, and for a long time after the war.  Most of these were fairly dangerous- one side of the chassis is connected to one side of the AC line.  This means that touching anything metal on the radio can result in a shock.  In the early 40's, companies like Philco and Zenith experimented using new rubber wiring... which has almost all disintegrated by now!

After the war, the public was eager to buy new radios to replace their out-of-style 30's models.  Companies were eager to sell, and created some wild designs, like the 1947 Emerson 'Moderne', and 1948 Philco 'Hippo'.  Most of these radios were little different electronically from the ones people were replacing, but they sure looked different!

1941 RCA BP-10

1941 Zenith Poketradio 4K600

1946 Air King

1946 Bush DAC90

1946 Firestone Air Chief

1946 RCA 54B2

1946 Westinghouse 578 'Astra'

1947 Emerson 'Moderne'

1947 Murphy 122

1947 Zenith