<VV>Transistor Radios

[Padgett]

Delco radios actually went through several transitions in the 50s and 60s
1) high B+ voltage tube type radios with vibrators (pre-1957)
2) low voltage (12v B+) radios - 1957-1959ish (not at home so cannot look up)
3) low voltage tubes with a single transistor output (1959-1962)
4) all transistor radios (1963 model year)

Keep in mind that until the late fifties, transistors were considerably more expensive than tubes and used only in high-end sets.

Padgett