I spotted this recently in a newspaper from 1922:
A St. Louis family has named the baby Radio. It is probably adept at broadcasting.
In fact, I’ve seen this in several old newspapers. In the joke section. Whether or not a St. Louis baby was actually named Radio in 1922 I have no idea.
There certainly have been babies named Radio, though. The name has never appeared on the SSA’s baby name list, but the Social Security Death Index indicates that there have been at least nine Radios. Most were born before audio broadcasting really began to take off in the early 1920s, so I don’t know how many (if any) were named with a household radio in mind.
Source: Prescott Evening Courier 23 Jun. 1922: 4.
Related: Baby Names from Radioland